Wednesday, September 21, 2011

Chemistry with buffers?

A beaker with 100 ml of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 7.30 ml of a 0.360 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.Chemistry with buffers?
pH = pKa + log (base/acid)



5.00 = 4.76 = log (x/1)



I want the ratio of base to acid which is why I used x/1



log x = 0.24



x = 1.74



my base:salt ratio is 1.74:1



let x = moles of acid



1.74x + x = 0.01 total moles of solute



x = 0.00365 moles (this is the acid)

base = 0.00635 mol



Add strong acid, it protonates the base



(0.360 mol/L) (0.00730 L) = 0.002628 mol of strong acid added



base: 0.00635 - 0.002628 = 0.003722

acid: 0.00365 + 0.002628 = 0.006278



pH = 4.76 + log(0.003722/0.006278)



pH = 4.53



Note: I used moles in that last H-H expression rather than using the new volume of 107.3 mL to get molarities. Since there would be a 0.1073 L in the numerator and the denominator, I just skipped that step.



Good problem. Check my math carefully and talk the solution through with your study group. Best wishes.



Update:



http://www.chemteam.info/AcidBase/Hender



problem #7

Chemistry help please?

A beaker with 175 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M . A student adds 6.90 mL of a 0.340 M HCL solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760Chemistry help please?
let x = [acetic acid]

let y = [acetate]



5.00 = 4.760 + log y/x

10^0.24 = y/x

1.74 = y/x

1.74 x = y



but we know that x + y = 0.100

y = 0.100-x

1.74 x = 0.100-x

2.74 x = 0.100

x = 0.0365 and y = 0.0635 M



moles acetic acid = 0.0365 x 0.175 L=0.00639

moles acetate = 0.0635 x 0.175 L=0.0111



moles H+ added = 6.90 x 10^-3 L x 0.340 M=0.00235

the reaction that occur is

CH3COO- + H+ = CH3COOH

moles acetate = 0.0111 - 0.00235 =0.00875

moles acetic acid = 0.00639 + 0.00235 =0.00874

total volume = 6.90 + 175 = 181.9 mL =%26gt; 0.1819 L

[acetic acid ] = 0.00874 / 0.1819 =0.0480 M

[acetate] = 0.00875/0.1819 =0.0481 M



pH = 4.760 + log 0.0481 / 0.0480=4.76

Chemistry Acid Base Buffer?

A beaker with 155 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 7.60 mL of a 0.260 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.Chemistry Acid Base Buffer?
let x = [acetate]

let y = [acetic acid]



x + y = 0.100



5.00 = 4.760 + log x/y



5.00 - 4.760= log x/y



10^ 0.24 =1.74 = x/y



1.74 y = x



1.74 y + y = 0.100

2.74 y = 0.100

y=0.0365 M

x = 0.100 - 0.0365=0.0635 M



moles acetate = 0.0635 x 0.155 L=0.00984

moles acetic acid = 0.0365 x 0.155=0.00566



moles H+ added = 7.60 x 10^-3 L x 0.260=0.00198



CH3COO- + H+ = CH3COOH

moles acetate = 0.00984 - 0.00198=0.00786

moles acetic acid = 0.00566 + 0.00198=0.00764



total volume = 0.1626 L

[acetate]= 0.00786/ 0.1626=0.0483

[acetic acid]= 0.00764/ 0.1626=0.0470 M



pH = 4.760 + log 0.0483/ 0.0470=4.77



delta pH = 0.23

Do you think it's safe to put flagstone in a goldfish tank?

Hi,

i was wondering if it's safe to put it and build it. its a 20 gallon goldfish aquarium! a few question!

is it safe for the goldfish?

will it put to much pressure on the glass? (it's about 70 pounds)

how do i clean it fist

and will it change the PH?

is it safe for goldfish????!?!?Do you think it's safe to put flagstone in a goldfish tank?
Should be fine. Just be careful with the weight. Seventy pounds is a bit too much for a twenty gallon tank, just be sure not to put any ';points'; directly on the glass which would create a pressure crack. If you're laying it flat, no problem. I'd go with small/medium pieces, around six-eight inches, and stack them mabey halfway up the tank. A few could reach the surface. Leave the front half of the tank empty. This shouldn't be too much weight. Glass is stronger than most people think. If you have bubble-eye goldfish, be sure there are no sharp edges that could burst their bubbles! Just rinse it off in warm water to remove the dust.Do you think it's safe to put flagstone in a goldfish tank?
Why on earth would you want to do that?

Challenging Pure chemistry?

When volume of acid was added to an alkali, how does pH change during the acid -base titration?



Thank you very much for your help.Challenging Pure chemistry?
';The pH will level off';??? I don't believe that Rhiz has ever done a titration. There is no ';leveling off'; at the equivalence point. Take a look at the graph of pH vs volume of added base for the titration of an acid.

http://library.tedankara.k12.tr/chemistr

or this one for the titration of a base by an acid:

http://www.chem.ubc.ca/courseware/pH/sec



Challenging Pure chemistry?
The pH will decrease progressively...



Should this be a strong acid-strong base titration, the pH will decrease progressively then rising or descending sharply (equivalence point) along pH 7...



In a strong acid-weak base titration... the drastic descent or equivalence point will be below pH 7...
It Depends On the Buffering Capacity.
There is a non-linear response. pH changes relatively rapidly until you reach a buffering point (not really a point), a narrow pH range where the dominant compound undergoes an ion change by the addition of H+ to the base form. the pH where this occurs depends on the stability relations between the H-base and H-free base ions. You see only a slight pH change in the immediate vicinity of this point because the H+ that is added is essentially immediately combined with the base ion. after you have converted essentially all of the base to the H-base, the pH will again change rapidly.

Advice needed for sick drawf (freshwater) puffers.?

African (Malawi) cichlid tank. 75 gallons, established. PH 7.5-8.0. Chichlid salt used. No plants, only rockscape. Bought 6 puffers ~8 weeks ago. Feed mosquito larvae, brine shrimp, krill. I feed them once a day. Occasionally skip a day. Also pellet, flake, cichlid food. The puffers don't seem to eat these. No signs of illness. No problems with other fish in the tank. Found three of the puffers dead, two days ago. One is now sick. THe other two lay on the bottom but seem to have revived and are swimming around None of them have looked sick- no ich, fungus, etc. Help. I really like these guys and am not sure what to do. Is the Ph too high for them? Not enough or too muh salt? No cover? Wrong food? looked them up on the net but cannot find the answers to these questions. I have a community tank and a guppy tank I could move them to if the ph is an issue (they are 7.0)- but if so, how do you do it without shocking them by the ph change? Any suggestions would be appreciated.Advice needed for sick drawf (freshwater) puffers.?
dwarf puffers could be taking each other out -- they aren't very social and are better with heavy plants if kept in groups. from my understanding they are salt sensitive anything over a teaspoon and 1/2 in 10 gallons would be a problem.Advice needed for sick drawf (freshwater) puffers.?
Puffers should have absolutely no salt content. They are also solitary fish and would have double the stress in this big, stocked tank.
kill it. If you touch it then u will grow a fin and ure legs will be gone and then u will have a huge head and then u will eat something and it will mutate inside of u and you will become a fish!!!!!!!!!!!!!!

































jking. YA just no salt 4 him.
  • Decorating the bedroom need some ideas
  • slightest effect
  • Chemistry help please?

    A beaker with 175 ml of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100M . A student adds 6.90 mL of a 0.340 M HCL solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.



    Basically whats delta pH?Chemistry help please?
    let y = [acetate]

    let x = [acetic acid]



    5.00 = 4.760 + log y/x

    10^0.24 = 1.74 = y/x

    1.74 x = y

    but we know that y + x =0.100



    1.74 x = 0.100-x

    x = 0.0365 M

    y = 0.0635 M

    moles acetic acid = 0.0365 x 0.175 L= 0.00639

    moles acetate = 0.0635 x 0.175 L= 0.0111

    moles H+ added = 6.90 x 10^-3 L x 0.340 M= 0.00235

    CH3COO- + H+ = CH3COOH

    moles acetate = 0.0111 - 0.00235 = 0.00875

    moles acetic acid = 0.00639 + 0.00235 = 0.00874

    pH = 4.760 + log 0.00875 / 0.00874 = 4.76



    delta pH = 5.00 - 4.76=0.24

    Common ion effect question?

    What is the Ph change of a 0.210 M solution of citric acid pka equals 4.77 If citrate is added to a concentration of 0.150 M with no change in volume?



    please does anyone have any idea on how to solve this?Common ion effect question?
    well, the best way to do this would be the hendersson hasslebach equation, which is pH = pKa + log(A-/HA). in this cause, you first need to know how much of the original 0.210M citric acid dissociates in a solution. Therefore, make a chart that helps you show how much citric acid dissociates base on it's Ka1. After that, you would add 0.150M citrate. Based on the rules of equilibrium, the equation will work to balance this effect, and you need to balance the effects by changing the concentration of HA and A-, which is how you get the values for the equation.

    Is a weak acid on (its own) a buffer?

    When text books explain how a weak acid buffer opposes the effect of the addition of an alkali they tend to refer to how the alkali reacts with and removes H+ ions but then the weak acid deprotonates to replenish these H+ ions (Le Chatalier's principle). This explanation does not rely on or require the salt of the weak acid!



    Put simply: Would a weak acid solution (without its corresponding salt) act as a buffer opposing a change in pH on addition of an alkali?Is a weak acid on (its own) a buffer?
    It would oppose a change in pH on the addition of an alkali. However, a real buffer is supposed to resist all changes in pH, in response to the addition of acid also. The above is NOT an actual buffer; you need the weak acid AND it's conjugate base to be able to buffer a solution. It is an BUFFERING AGENT, A buffering agent is used to adjust or stabilize an acidic or basic solution, by CHANGING it's pH. On the other hand a buffer solution MAINTAINS the pH of the solution.Is a weak acid on (its own) a buffer?
    weak acid %26amp; weak base salts are buffers....not a weak acid acts as a buffer ........ neutralization theory explains this
    Have to agree with a previous post. It would oppose the change of pH when adding alkali, but there will simply not be enough of the conjugate base present (because the acid is weak!) to oppose a change in pH when acid is added.

    Where does Ick come from?

    I've actually put this hear to explain how the disease works. I had made a response to a previous question, and someone said they didnt know why I thought ph had anything to do with ick. Actually Ick is a parasite that all fish carry, but break out with when stressed. Usually any drastic change in ph or tempature will bring on an ick breakout.

    Ich is a ciliated protozoan parasite that infests freshwater tropical fish, goldfish, koi, and other gamefish species. Ich is a relatively large protozoan, up to one mm in diameter. Ich infestations can wipe out an entire tank of fish or pond if left untreated.

    The most common symptom is the appearance of white spots on the fish. The spots can be seen on fins, the body, and eyes of the fish. Infested fish may not immediately show the characteristic white spots. Ich infests the gills, feeding on cells and fluids. Gill tissue suffers extensive damage, leading to suffocation of the fish.

    Ich also infests the body and fins and can lead to secondary bacterial and fungal infections. In the early stages of infection fish may be seen scratching on ornaments, rocks, or gravel. In the later stages fish are often seen hanging near power filter outlets, pumping their gills, in an attempt to get oxygen. Some fish may sit of the bottom of the aquarium or pond. Infested fish often will not eat.

    Ich parasites burrow just under the skin of fish, causing the characteristic ';white spot'; or trophont stage. At maturity, the adult parasite, called a tomont, detaches from the fish and swims freely for about six hours. The trophozite eventually settles to the bottom of the aquarium. The parasite then secretes a protective membrane. The ';cyst'; now undergoes many divisions, producing 1,000 or more offspring, called theronts. When the cyst breaks open, up to 1000 theronts emerge in search of a fish host. Theronts invade their fish host by burrowing into the skin with their cilia and digestive enzymes. The tomites feed on fish cells and tissue fluids until mature, starting the cycle over again. Tomites especially devastating to delicate gill tissue. The gills are destroyed by the destructive feeding action of the parasites, causing the fish to suffocate.



    Considering that each trophozite releases about 1000 infective theronts, it is easy to see how fish can quickly succumb to an Ich outbreak. Water temperature controls the speed of the Ich life cycle. At 21掳 -24掳 C (70掳 -75掳 F) it takes about three days for a complete cycle.

    Ich parasites can only be killed when they are in the free-swimming theront stage. Medications do not kill the parasites attached to the fish (white spot) or when the parasites are encysted in the gravel. Disappearance of the white spots simply means that the parasites have advanced to the cyst stage. In a few hours or days, depending on water temperature, thousands of infective theronts will burst out in search of a fish host. It is precisely at this point that the medication does its job. Since not all the Ich parasites ';hatch out'; at the same time, it is necessary to treat the aquarium or pond for several days to insure control. When one fish has ick, all fish in the aquarium or pond will be infected. All fish must be treated. Ich parasites are easily transferred to other aquaria or ponds by nets, hands, boots, etc. Quarantine the infested fish. Do not add or remove fish from the infested aquarium or pond. Begin treatment immediately.Where does Ick come from?
    Ich is not always present on all fish. It is not a disease. It is a parasite. It is temperature sensitive. It's life cycle is 7 days.



    If you raise the temp to 86 degrees and don't see any white spots on your fish for 10 days, the parasite has died out in your tank and cannot reinfect unless you add an infected fish or a plant/decoration from an infected tank.



    A holding tank for new fish and plants is a must. Two weeks is the absolute minimum to house the new fish/plant in the holding tank. Remember, 7 days is the life cycle of the ich parasite. Other diseases or parasites may present during this time also, or even in the third week. Many top authorities in the field of fish diseases and parasites reccommend a 4 week period in the holding tank before adding the newcomers to your community tank.



    If you have already tried medication without results, there is another way to cure ich. The other approach is to actually destroy the organism with heat, and can be combined with the salt treatment, but not with meds.



    The data that was studied (including a report by the Southern Regional Aquaculture Center) suggests that most strains of Ich cannot reproduce at temperatures above 85潞F. To use this temperature treatment approach, slowly (no more than 1 or 2 degrees per hour) raise the temperature to 86潞F, while maintaining strong continuous surface agitation to oxygenate the water.



    This is extremely important because water holds less O2 at higher temperatures. (This is why meds should not be used in conjunction with high temp ?most Ich treatment products also reduce oxygen levels. Less available oxygen, combined with the respiration difficulties an infected fish is already faced with, could be fatal.)



    The adjusted temperature should be maintained for approximately 10 days, or a minimum of 3 days after all signs of the parasite have disappeared (the life cycle of the parasite is 7 days).



    Do not discontinue treatment when the spots go away. This is critical, because we know that the parasites are visible only as a white spot (trophont) on the body of the host, and not during the reproductive or free-swimming stage. We also know that trophonts on the gills are impossible to see.



    Salt inhibits all freshwater parasites and is commonly used with many livebearers to keep them healthy. Most fish benefit from salt in their water, but some are affected detrimentally. Do your research before adding salt to any tank.Where does Ick come from?
    I stand corrected.



    I do however stand by the fact that different fish have different Ph requirements. But that is not the point here.



    EDIT: Nevermind, this is not your own writing. http://badmanstropicalfish.com/meds/ick.
    I think this is the best fish website I've seen, please join the forum
    Boy lots of false information here in the question and also in the responses.



    Here is a good article on Ich.



    http://www.aquaria.info/index.php?name=N
    first off be assured all fish do not carry ich. Ich is a free swimming parasite. The only way to totally elimate it is to have a sterilizer on your tank. Also where did you get your info? Research better. Ich can also affect saltwater fish. Perhaps you need a better web site or should I say more than one to figure out what exactly you are tryin to say. Good copy from a web page however you missed many different items. The web page where you got your info was from a novis not a pro. This is the problem with surfing the web. Don't take the info that sounds like what you want to hear, take what is correct. Ich does not attach itself to non stressed fish. NO MATTER what this web page says. Medications DO kill the free swimming form as well as a sterilizer. Where did you get this crap from? Disapperance of the white spots, right does not mean it is cured but they have not necessarily ';Moved on to another stage.'; GOD you people will believe anything. Water temps don't mean didly. Sterilize and treat, however Kick ich may be way beyond your financial means, then again, if this quack diesn't recommend it it must not be true. Quarantine a fish after the entire tank is infected? that is a smart move bowles. Each medication is different. There is no host fish, they all are treated as such. I think you need to go back to aquarium 101 hun since apparently you didn't learn anything the first time around. AND QUIT surfing web pages and taking the crack pot sites as fact. No wonder your tanks die. You should not be allowed to have fish until you learn how to actually care for them. What a waste of time and typing.
    I am not sure......all I know is that it is a disease(for fish of course).

    good luck!

    Adding strong acid to buffer?

    A beaker with 165mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100M . A student adds 9.00mL of a 0.250M solution to the beaker. How much will the pH change? The of acetic acid is 4.760.Adding strong acid to buffer?
    0.100 M * 165 mL = 16.5 mmoles CH3COOH and CH3COONa.



    I'm going to assume that you're adding 9.00 mL 0.250 M strong acid to the solution.



    9.00 mL * 0.250 M = 2.25 mmoles HCl



    The strong acid will react with the conjugate base form to produce more weak acid.



    16.5 mmoles CH3COONa - 2.25 mmoles HCl = 14.25 mmoles CH3COONa leftover.



    16.5 mmoles CH3COOH + 2.25 mmoles CH3COOH created = 18.75 mmoles CH3COOH



    Use the Henderson-Hasselbalch equation to find the new pH:



    pH = pKa + log[A-/HA]



    You normally would convert the new mmoles to concentration, but you do not have to because this is a ratio between the two.



    pH = 4.760 + log(14.25/18.75) = 4.64



    Since the solution before the addition of the acid is an even mixture of acid and conjugate base, the pH = pKa initially.



    So the change in pH would be:



    dpH = pHf - pHi = 4.64 - 4.76 = -0.12

    Adding strong acid to buffer?

    A beaker with 105ml of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100M . A student adds 6.60ml of a 0.360M solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.Adding strong acid to buffer?
    5.00 - 4.76=0.24



    10^0.24 =1.74 = [acetate]/ [acetic acid]



    [acetate]= 1.74 x [acetic acid]



    [acetate] + [acetic acid]= 0.100



    [acetic acid]= 0.100- [acetate]



    [acetate]= 1.74 ( 0.100 - [acetate] = 0.174 - 1.74 acetate



    [acetate]= 0.0635 M

    [acetic acid ]= 0.0365 M



    moles acetate = 0.105 L x 0.0635 =0.00667

    moles acetic acid = 0.0365 x 0.105 L=0.00383



    now the student add 6.60 mL of a 0.360 M of ???

    hope helps
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  • Adding strong acid to buffer?

    A beaker with 105ml of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100M . A student adds 6.60ml of a 0.360M solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.Adding strong acid to buffer?
    5.00 - 4.76=0.24



    10^0.24 =1.74 = [acetate]/ [acetic acid]



    [acetate]= 1.74 x [acetic acid]



    [acetate] + [acetic acid]= 0.100



    [acetic acid]= 0.100- [acetate]



    [acetate]= 1.74 ( 0.100 - [acetate] = 0.174 - 1.74 acetate



    [acetate]= 0.0635 M

    [acetic acid ]= 0.0365 M



    moles acetate = 0.105 L x 0.0635 =0.00667

    moles acetic acid = 0.0365 x 0.105 L=0.00383



    now the student add 6.60 mL of a 0.360 M of ???

    hope helps

    Chemistry help please?

    Explain what is in a buffer. Discuss the function of a buffer. How will pH change when small amounts of acids or bases are added to the buffer solution?Chemistry help please?
    a pH buffer is a substance added to a reaction to keep it at a certain pH. Otherwise in some reactions they change the pH themselves thus sometimes inhibiting the reaction. For example the enzyme lipase breaks down fats into fatty acids and glycerol. But the enzyme itself can only work in an alkali condition. So when it breaks down the fats,the fatty acids would change the pH to acidic and so the enzyme would no longer work- bile is the pH buffer in our body.



    So back to your question. A pH buffer keeps the pH constant at the set pH wanted by the experimenter, despite any changes in the pH caused by the reaction.Chemistry help please?
    I guarantee you that this question is answered in one or two paragraphs in your textbook. Look up buffer in the index. It all has to do with the percentage of Hydrogen ions involved, hence the term p for percentage, H for Hydrogen, or pH. Think of how many positive ions it would take to neutralize all of the negative ions / or vice versa. Kinda like doing addition with positive and negative numbers in the same equation. It's in the book. Look it up.

    I need help with science! please!?

    if the base is added to an acidic solution, how will the pH change-increase, decrease or stay the same?I need help with science! please!?
    An acidic solution is that smaller than 7pH and a basic solution is larger than 7pH. So is a base is added to an acid you get a neutralization curve and you approach neutral pH. Number gets larger.I need help with science! please!?
    First, always remember A-A....Add Acids to bases, don't add bases to acids. It's a standard rule in chemistry. Anyway, the pH of the acid would increase if you add a base to it. It was low to begin with, now you're adding a base (high pH). Also, remember small p, large H....pH....not being picky, but if you run inot someone picky about these things, it might matter. Add acid, and call it pH.

    Adding strong base to basic buffer solution.?

    What will be the pH change when 20.0mL of 0.100 M NaOH is added to 80.0mL of a buffer solution consisting of 0.169 M NH3 and .183 M NH4CL?



    I calculated that before the NaOH is added the pH is 9.29 but I don't know how to do the rest.Adding strong base to basic buffer solution.?
    Okay, so what you have to do here is find the moles of NaOH and the moles of your initial acid and base, find the new molarities after the change, and use the henderson-hasselbalch equation with your new concentrations.



    so for the initial pH, i used pKa of NH4Cl (9.3).



    pH = 9.3 + log (0.169M/0.183M), and I found the pH to be 9.265, which is a little different.





    then, I found the moles of NaOH using M = mol/L



    0.1M = x mol/0.02L, and found the moles to be 0.002.



    after finding the moles of NaOH, i did the same method to find the moles of NH3 and NH4Cl, which were 0.0135 and 0.01464, respectively.



    when adding a strong base to a buffer, the acidic component reacts with the added base, causing OH- ions to be released and the moles of acid to decrease and base to increase, respectively.



    with this knowledge, I added the number of moles of NaOH to the moles NH3

    0.0135 + 0.002 = 0.0155 moles



    and subtracted the number of moles of NaOH from the moles of NH4Cl

    0.01464 - 0.002 = 0.01264 moles



    i then found the molarities of each by dividing the moles by (0.08 L + 0.02 L to account for the addition of NaOH), and found the new concentrations.



    [NH3] = 0.155M, [NH4Cl] = 0.1264M



    now that we have the new concentrations of acid and base, substitute them into the H-H equation to get the new pH:



    pH = 9.3 + log (0.155/0.1264) = 9.39.



    9.39 - 9.265 = a pH change of +0.125.



    there may be some minor errors in there, but that is how one generally figures out these problems. good luck!

    Problem Help! Henderson Hasselbalch equation.

    Here's the problem I am given: A beaker with 120mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.1M. A student adds 6.60mL of a 0.300M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.76.



    The main thing I'm having a problem with is figuring out how to find the moles of acid and base using the henderson hasselbalch equation. I found the ratio of conjugate base to conjugate acid (1.74) but that's as far as I've gotten. If someone could show me how to do that I would really appreciate it.



    Thanks for your help!Problem Help! Henderson Hasselbalch equation.
    Ok I would change thew molarity as it wree to mmoles of ...in other words the 120 mL X 0.1 M = 12 mmoles total for the two forms acid and base. Since the pH is 5 then the amount of each form can be determined by th following H/H 5.0 = 4.76 + log base /12 - base since the pH is merely a function of the ratio of mmoles since the two forms are in the same volume. so 5.0 - 4.76 = log base /12-base

    so 1.74 = base /12-base

    20.88 = 2.74 base base = 7.62 mmoles and acid = 12 - 7.62 = 4.38 moles



    check



    pH = 4.76 + log 7.62/4.38 = 4.76 + log 1.739 = 4.76 + 0.24 = 5







    so now the pH after adding the HCl will be driven more acidic because the ratio uis going to change 6.6mL x 0.3 M = 1.98 mmole of H+ so adding this to the buffer will convert 1.98 moles of the base form ( acetate ) to the acid form so the pH will now be



    pH = 4.76 + log[ 7.62-1.98]/4.38 + 1.98 mmoles = .76 + log 5.64/6.36

    = 4.76 -0.052 = 4.708 it changes by - .29 pH units

    How to get rid of weeds?

    I have a patch of weeds that I need to kill. I am going to put grass there so I don't want to change the pH of the soil. Is there a quick way to do this? How to get rid of weeds?
    everyone is right about needing to pull them out. the easiest way to do that is to thoroughly soak the base of the weed(s) by putting a hose on it (barely turned on) for about 10 minutes, and in many cases you can just grab the weed at the base and pull it out, root and all. use a weed knife to make sure you get the entire root. don't shake the weed once you get it out, throw the entire thing away, dirt and all, to ensure you don't drop any seeds. weed killer usually puts the root into hibernation mode, and it will thrive once again with enough watering. How to get rid of weeds?
    You could dig for their roots. That way, the weeds can't grow back. I suggest a hoe if it grew to an amazing height.
    The safest and most efficient way is to take a shovel and dig them up by roots and all and shake the dirt back out. Some people prefer chemicals but they are bad for your soil and the bees. If it's a larger area use a rototiller and then rake out as much of the weeds as you can and throw them in a compost pile elsewhere.
    The quickest way, of course, is to till the weeds under with a roto-tiller, but if you were wondering about weed killer, you could use that too without changing the pH of the soil. You have to prep the soil for the new lawn seed anyway, so...remove the big weeds and till the rest under. The new lawn should choke out the weeds once it is established.
    I use an herbicide called 2-4d it won't affect grass,ponds,wildlife,or house pets but kills weeds quick.
    Pour boiling water on them. They will be brown the next day, then dig them up and make sure you get all the roots.



    Good Luck!
    If the weeds are green %26amp; activly growing us shuld use ';Roundup'; - very effective %26amp; breaks down quickly.
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  • Please explain what is in a buffer...?

    and discuss the function of a buffer.

    How will pH change when small amounts of acids or bases are added to the buffer solution?Please explain what is in a buffer...?
    A buffer is a solution of a weak acid and it's conjugate weak base. The pH of the buffer is such that it is within one pH unit of the pKa of the acid (aka the weak acid and weak base forms are present in near-equal amounts). This means that when you add small amounts of acid or base to the buffer, the weak acid/base will sort of ';soak up'; the extra H+ (or OH-) ions and the result will be little to no change in the pH of the solution.



    So the purpose of a buffer is to make a solution where the pH stays stable even when small amounts of acid or base are added.

    Adding a Strong Acid to a Buffer?

    have the solution, but I still dont understand some of the steps.



    A beaker with 115mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.1M . A student adds 4.30mL of a 0.490M HCl solution to the beaker. How much will the pH change? The Pk_a of acetic acid is 4.76.





    SOLUTION:



    pH = pKa log acetate / acid

    5.00 = 4.76 log acetate / acid



    acetate / acid =10^0.24= 1.74

    acetate acid = 0.1



    Solve the system

    acetate = 0.0365 M

    acid = 0.0635 M



    *HOW DID THEY FIND THAT IT'S .0365 M %26amp; .0635 M???

    *CAN SOMEONE SHOW ME HOW TO THE MATH FOR IT?????



    moles acetate = .115 L x 0.0365 M = 0.00420 mol

    moles acid = .115 L x 0.0635 M = 0.00730 mol



    Moles H added = .00430 L x 0.490 M = 0.00211mol

    CH3COO- H --%26gt; CH3COOH

    moles acetate = 0.00420 - 0.00211 = 0.00209 mol

    moles acid = 0.00730 0.00211 = 0.00941 mol



    *WHY SUBTRACT FOR ACETATE BUT THEN ADD FOR ACID??



    Total volume = 115 4.30 = 119.3 mL = 0.1193 L

    concentration acetate = 0.00209/0.1193 = 0.0175 M

    concentration acid = 0.00941 / 0.1193 = 0.0789 M



    pH = 4.76 log 0.0175 / 0.0789 = 4.11Adding a Strong Acid to a Buffer?
    [CH3COO-] / [CH3COOH] = 1.74

    [CH3COOH] + [CH3COO-] = 0.1



    [CH3COO-] = 0.1 - [CH3COOH]



    We put this value in the 1st equation :

    0.1 -[CH3COOH] / [CH3COOH] = 1.74



    we multuply the left and the right side by [CH3COOH]



    0.1 - [CH3COOH] = 1.74 [CH3COOH]

    0.1 = 2.74 [CH3COOH]

    [CH3COOH] = 0.0365 M



    [CH3COO-] + 0.0365 = 0.1

    [CH3COO-] = 0.1 - 0.0365 = 0.0635 M



    the effect of the added 0.00211 mol of H+ would be to decrease the moles of CH3COO- by 0.00211 and increase the moles of CH3COOH by 0.00211 by the reaction :

    CH3COO- + H+ %26gt;%26gt; CH3COOH

    Adding a strong acid to buffer?

    A beaker with 200 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 6.20 mL of a 0.260 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.



    please help??? I'm lost....Adding a strong acid to buffer?
    5.00 = 4.760 + log [CH3COO-] / [CH3COOH]



    10^0.24 = 1.74 = [CH3COO-] / [CH3COOH]



    [CH3COOH] + [CH3COO-] = 0.100



    [CH3COOH] = 0.100 - [CH3COO-]



    1.74 = [CH3COO-] / 0.100 - [CH3COO-]



    0.174 - 1.74 [CH3COO-] = [CH3COO-]



    [CH3COO-] = 0.0635 M

    [CH3COOH]= 0.100 - 0.0635 =0.0365 M



    moles acetate = 0.200 L x 0.0635 =0.0127

    moles acetic acid = 0.200 x 0.0365 =0.00730



    moles HCl = 0.00620 L x 0.260 M=0.00161



    CH3COO- + HCl %26gt;%26gt; CH3COOH

    moles acetate = 0.0127 - 0.00161 =0.0111

    moles acetic acid = 0.00730 + 0.00161 =0.00891

    total volume =0.206 L

    cocnentration acetate = 0.0111 / 0.206 =0.0538 M

    concentration acetic acid = 0.00891 / 0.206 =0.0433 M



    pH = 4.760 + log 0.0538 / 0.0433 =4.85

    Suppose a mixture's hydrogen ion concentration is increased by a factor of 100...?

    ...By How much and in what direction will the pH change?



    its to the left right? but is it by 100? or am i missing something?



    (Ok, my last algebra question for the night, I've been spending hours on this, now it's almost 2 AM and I need to know what is going on so I can get some sleep and go to class at 8 AM. Can anybody help me out here? It would be SO appreciated. Thanks)Suppose a mixture's hydrogen ion concentration is increased by a factor of 100...?
    The pH will change by two. It will go down. If you start out at pH 5 you will end up at pH3.

    pH is defined as the negative log ouf the hydrogen ion concentration. If it changes by a factor of 100, the log changes by two. If the concentration goes up, the pH will go down.Suppose a mixture's hydrogen ion concentration is increased by a factor of 100...?
    think you mean by a factor of 10 not 100.
    pH is log (base 10) hydrogen ion concentration



    log 100 is 2



    so pH is altered by 2 and more acid so reduced by 2 (to the lefT)

    Chemistry question involving buffers?

    A beaker with 175mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100M . A student adds 6.80mL of a 0.430M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.Chemistry question involving buffers?
    [CH3COOH] + [CH3COO-]= 0.100 M



    pH = pKa + log [CH3COO-] / [CH3COOH]



    5.00 = 4.760 + log [CH3COO-] / [CH3COOH]



    10^0.24 =1.74 = [CH3COO-]/ [CH3COOH]



    solving this system

    [CH3COO-] = 0.0635 M

    [CH3COOH]= 0.0365 M



    Moles acetate = 0.0635 M x 0.175 L=0.0111

    moles acetic acid = 0.0365 M x 0.175 L= 0.00639



    moles HCl = 0.00680 L x 0.430 M=0.00292



    CH3COO- + H+ %26gt;%26gt; CH3COOH

    moles acetate = 0.0111 - 0.00292 =0.00818

    moles acetic acid = 0.00639 + 0.00292 =0.00931



    total volume = 175 + 6.80=181.8 mL = 0.1818 L



    [acetate]= 0.00818 / 0.1818 = 0.0500 M

    [acetic acid ]= 0.00931 / 0.1818 = 0.0512 M



    pH = 4.760 + log 0.0500/ 0.0512 = 4.750

    Adding strong acid to a buffer

    A beaker with 175 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.1M. A student adds 7.30 mL of a 0.340M solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.76.Adding strong acid to a buffer
    5.00 = 4.76 + log [CH3COO-] / [CH3COOH]

    [CH3COO-] / [CH3COOH] = 10^0.24 = 1.74



    [CH3COO-] + [CH3COOH] = 0.1

    [CH3COO-] / [CH3COOH] = 1.74



    solving this system we get [CH3COO-] = 0.0635 M and [CH3COOH] = 0.0365 M



    Moles CH3COO- = 0.0635 x 0.175 = 0.0111

    moles CH3COOH = 0.0365 x 0.175 = 0.00639



    Now you forgot to say if the solution is an acid or a base so I can not answre at your question but I thing that this can help you
  • store properties
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  • What do buffers do, and why are they important in biological systems?

    This is related to bio 181 regarding an exparment with pH levels. I am not shure how to relate it to the biological system. in most organisms, the pH is kept relatively constant by buffers. buffers minimize changes in pHWhat do buffers do, and why are they important in biological systems?
    Buffers are chemicals that make a solution capable of absorbing large amounts of acid or base without experiencing any change in pH. You can doubtless pull better definitions out of any of the numerous online dictionaries.



    Buffers are important to biological systems because they enable the organism to maintain homeostasis (you have to include that word in your answer) with little physiological cost.



    By enabling cells or systems to absorb chemical changes without experiencing pH changes buffers make it possible for organisms to survive in variable environments without wasting vast amounts of energy trying to monitor and adapt to every minor change in physical conditions. They similarly allow organism to engage in activity that will cause the addition of large quantities of acids and bases without risking death or wasting resources trying to deal with it. Most notably they allow organisms to tolerate the acid build up associated with respiration as well as allowing the consumption of acid or alkaline foodstuffs.



    Tack on a brief description of the carbonate buffer system in the mammalian blood and you檙e good to go.What do buffers do, and why are they important in biological systems?
    Buffers are substances that have specific salt levels to regulate osmosis and to maintain a specific pH. A practical example, cells can shrink or explode when there is too much/too little salty liquid on the inside or outside of the cell, a buffer can regulate the cell system. (look up turgid)
    If the pH of a system gets out of whack, many chemical reactions that occur in an biological system will behave much differently. So, for example, if some function can only occur in an environment with a pH between 5.5 and 5.8, a buffer will ensure that the pH is kept within that range.
    Don't forget to consider the sensitivity of enzymes to pH (the affect of pH on enzyme activity).

    This applies to both intra- and extra-cellular proteins too; cytoplasmic pH and plasma pH must be stabilised.
    you got great answers from everyone. I'd add from experience that when you are checking the pH, either in blood (biological system) or in the lab (inorganic system, ie test tube), you should be aware of your breathing as a source of error. Hold your breath if possible, the CO2 did throw off my data considerably when I did a similar experiment.

    How will addition of sodium acetate to an acetic acid solution affect the pH?

    How will addition of sodium acetate to an acetic acid solution affect the pH?

    A) It will lower the pH.

    B) The pH will not change.

    C) The solution becomes hotter.

    D) The pH cannot be measured.

    E) It will raise the pH.How will addition of sodium acetate to an acetic acid solution affect the pH?
    sodium acetate acts as a buffer.



    therefore...



    b) the pH will not change

    How do I create a chart showing changes in pH throughout the soil profile?

    See link for a picture showing the graph I need to create. You may need to copy and paste it into your web browser:



    http://picasaweb.google.com/lh/photo/M90jw_FbDulGPyHsjclbayk6nStoJZqA55zKxJFDhSc?feat=directlink



    I have no idea how to do this, after trying lots of different things in excel 2007 and 2010, googling and reading up in excel 2007 for dummies I am still none the wiser on how to make this style graph.



    For example: The following data relates to salinity levels at certain depths in a soil profile, which are measurements of electrical conductivity at 1:5 ratio and expressed as dS/m.



    0.0001 - 5.5 cm

    0.0930 - 17.5 cm

    0.0364 - 20.5 cm

    Gravel - 23

    0.0005 - 50.5 cm

    0.0410 - 75 cmHow do I create a chart showing changes in pH throughout the soil profile?
    It's actually very simple. What you have to do is enter all the values in columns. Normally, you put soil depth in the first column, because it is the independent variable and should go on the X-axis. You select the values you want to use, and select ';scatter plot'; from the options in the chart menu. In Excel 2007, go to the ';Insert'; tab and select scatter as your option.



    To include a ';false point';, you have to plot a second data series on the same chart. Simply right-click the chart, select ';Select Data'; as your option, and add a series that will include the rogue point.



    Hope that helps. If you need more help, drop me a line and I'll help you further.

    Adding a strong acid to a buffer

    A beaker with 195 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.1 M. A student adds 8.80 mL of a 0.320 \it M \rm HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.76. I have such a hard time with this stuff PLEASE HELP!!!!Adding a strong acid to a buffer
    the total mmoles of th base and the acid form must total to 195mL x 0.1M = 19.5 mmoles

    pH = pKa + log base /acid



    5 = 4.76 + log base /19.5 - base

    0.24 = log base/19.5 -base

    1.737 = base/19.5-base solving for base 33.887=2.737Base

    base = 12.38 mmoles acid =19.5 -12,38 = 7.12 mmoles



    check



    pH = 4.76 + log 12.38/7.12 = 4.76 + 0.24 = 5



    adding 8.8 mL of 0.32 M acid is adding

    8.8mL x 0.32M = 2.816 mmoles adding 2.816 mmoles of acid will reduce the amount of the base in the numerator by 2.816 and add that same amount to the denominator so now

    the pH = 4.76 + log (12.38-2.816)/7.12 + 2.816 = 4.76 + - 0.0166 = 4.74Adding a strong acid to a buffer
    First you need to find the equilibrium concentrations of acetic acid and acetate. Use this equation:

    pH = pKa + log(base/acid)



    Let x be the concentration of acid at equilibrium.

    So .1 - x is the equilibrium concentration of acetate



    5.00 = 4.76 + log[(.1 - x)/x]

    x = .0365M



    Now we know the concentrations of all the parts of the buffer:

    Acetic acid is .0365M

    Acetate is .0635M

    Hydronium is 10^-5M (remember that the pH = -log[hydronium]



    Now multiply the concentrations by .195L to find out how many moles of each there are.

    Acetic acid is 7.1175x10^-3mol

    Acetate is .01238mol

    Hydronium is 1.95x10^-6



    Now add the total moles of hydronium from the HCl

    Since HCl is a strong acid, it completely dissolves, so the total moles of HCl equals the total moles of hydronium it yields.

    .320M x .0088L = 2.816x10^-3mol

    1.95x10^-6 + 2.816x10^-3mol = 2.818x10^-3mol



    Next find the new concentrations of all the reactants. Remember the new volume is .195 + .0088 = .2038L

    Acetic acid .0349M

    Acetate .0607M

    Hydronium .0138M

    Now use the pKa to find the Ka

    4.76 = -logKa

    Ka = 1.7378x10^-5

    This solution isn't at equilibrium. But we know that a certain amount of acetate and hydronium will react to form acetic acid until it is. Let that amount be x.

    1.7378x10^-5 = (.0138 - x)(.0607 - x)/(.0349 + x)

    x = .013782M



    .0607 - .01378 = .04692M

    -log.04692 = 1.33




    Adding a strong acid to a buffer

    A beaker with 175 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.1M. A student adds 7.30 mL of a 0.340M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.76.



    Any help would be appreciated.Adding a strong acid to a buffer
    the pH of the buffer is dependent only on the formal ratio of the base to the acid form by the relationshippH = pKa + log [base]/[acid]

    Since the total molarity is 0.1 and you have 175 mL of the buffer then the total mmoles of both forms together is

    175 x 0.1M = 17.5 mmoles so the ratio will be the base to the acid and the two forms must add up to 17.5 mmoles



    so pH = 4.76 + log base/17.5 - base

    5- 4.76 = log base /17.5 - base = 1.74 = base /17.5 -base



    base = 11.11 mmoles therefore acid = 17.5 -11.11 = 6.39



    check



    pH = 4.76 + log {11.11/6.39 } = 5.0002



    so adding 7.3 mL of 0.34 M HCl will add 7.3 X .34 = 2.482 mmoles of H+ to the buffer..This will increase the acid form of the buffer by reacting with 2.482 mmoles of the base form to produce 2.482 mmoles of the acid form..sooo the total mmoles will NOT change only the ratio will and thus the pH...





    soo pH = 4.76 + log{ (11.11-2.482 )}/ 6.39 + 2.482 = l4.76 + log 8.628/8.872 = 4.748







    Adding a strong acid to a buffer
    pH = pKa + log [CH3COO-] / [CH3COOH]



    5.00 = 4.74 + log [CH3COO-]/ [CH3COOH]



    [CH3COO-] / [CH3COOH] = 10^0.26 = 1.82



    [CH3COOH] + [CH3COO-] = 0.1



    we must solve this system :

    [CH3COO-] = 0.0645 M and [CH3COOH] = 0.0355 M



    moles CH3COO- = 0.0645 x 0.175 = 0.0113

    moles CH3COOH = 0.0355 x 0.175 = 0.00621



    CH3COO- + H+ %26gt;%26gt; CH3COOH

    moles HCl = 0.340 x 0.00730 L = 0.00248



    moles CH3COO- = 0.0113 - 0.00248 = 0.00882

    moles CH3COOH = 0.00621 + 0.00248 = 0.00869



    total volume = 0.1823 L



    [CH3COO- ] = 0.00882/ 0.1823 L = 0.0484 M

    [CH3COOH] = 0.00869 / 0.1823 = 0.0477 M



    pH = 4.74 + log 0.0484/ 0.0477 = 4.75

    Chemistry question please help?

    A strong acid solution has a pH of 4.0. The acid solution is mixed with water to make a large volume of solution.



    a) How will the concentration of hydrogen ions be affected?



    b) How will the pH change?



    c) How does dilution affect the pH of a basic solution?Chemistry question please help?
    Let's just use your example to figure out the answers to the questions.



    If the pH is 4.0 , according the the equation for pH:



    (incase you did not know, H3O+ is the same as talking about H+. Your teacher or professor might just use H+ to keep things simplified in class. But they are both the same thing (although H3O+ is a more accurate description of the acidic species). For this disucssion, we'll just use H3O+



    pH = - log [H3O+]



    we can find the concentration of the acidic species, H3O+.



    to find [H3O+] we need the opposite of the log function.



    [H3O+] = 10 ^-pH. That is, 10 raised to the power of negative pH.



    = 10^-4.0



    so [H3O+] = 1 x 10^-4 Molar or 1 x 10^-4 moles in every 1 L of water.



    So what happens if we increase the volume? Lets say we double it to 2 L. What will the concentration be if we have 2 L of water instead of 1?



    (1 x 10^-4moles) / 2 Liters = 5 x 10^-5. The concentration has decreased. (10^-5 is smaller than 10^-4).



    We have less moles of acid per 1 L (although we have more Liters overall).



    the new pH then is: - log (5 x 10^-5)



    pH = 4.30.



    So to answer Parts A %26amp; B:



    Increasing the Volume of solution will DECREASE the concentration of Hydrogen (H3O+) ions.



    And because of this, the pH INCREASES (or becomes less acidic or you can say just as easily the solution is becoming more basic).

    The pH changed from 4 to 4.30. It increased.





    PART C. Diluting a basic solution will have the same kind of opposite affect. Increasing the volume, will mean less moles of base per 1 liter of solution, so the concentration of OH- will DECREASE, and subsequently, the pH will slightly DECREASE towards the acidic range



    Less OH means more H+, so the pH decreases.
  • ie hosted control
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  • I have pink Hydrangeas and I wish to change them to blue. What PH level of acidity should the soil be?

    What should the PH level of the soil constantly be, if I want blue Hydrangeas? Do I have to water the plant everyday with the right PH level in the water? How long do I have to continue with this watering routine? Currently, I have many Hydrangea plants ranging from light powder pink to dark pink to light purple, to dark purple.I have pink Hydrangeas and I wish to change them to blue. What PH level of acidity should the soil be?
    Actually, instead of worrying about the pH in your water, it is much simpler to amend your soil to change the color of the hydrangea blossom.

    So if they are pink now, and you want them to be blue, add gypsum, sulphur or peat moss to create a more acidic environment (lower the pH).

    ';The flower color of big leaf hydrangea (Hydrangea Macrophilla) can be controlled by altering the soil pH. Blue flower color is produced by an acid soil condition (pH less then 6.5), while pink flower results from an alkaline soil condition (ph greater than 7.0).';

    You can raise the pH with oyster shells, lime or wood ash.

    Happy Gardening!

    (Your hydrangeas sound lovely!)I have pink Hydrangeas and I wish to change them to blue. What PH level of acidity should the soil be?
    I read once to change the color of hydrangeas, put a rusty nail or two in the dirt near the base of the plant (not in the plant).
    Try chemo therapy or radio therapy.

    %26amp; for ur soil above 11 ph
    Not too acidic. Use kitchen waste as compost. Yes it does have to be constantly acidic.

    Adding a Strong Acid to a Buffer?

    A beaker with 120 mL of an acetic acid buffer with a pH of 5.00 is sitting on a bench top. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 8.80 mL of a 0.270 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.Adding a Strong Acid to a Buffer?
    [8.00 / 5.00]

    Ans * .270 ===%26gt;%26gt;%26gt; Answer



    ? t??? ∩??? ?

    How can i decrease my gardens PH?

    I recently got my garden tested for PH which i used last year and my neighbors garden which he is just starting this year, both came out to 7.5 Alkaline. We probably shouldnt have been surprised because the valley we live in actually long ago used to be a limestone quarry. Our gardens are about 10,000sq ft. Mines in a square and his is in a rectangle. He used to have cows and i still have a few llamas so we both have what some might some consider fresh, and ';aged manure'; although i would think ';Aged'; means in some drying area but we dont do that. Anyways we are working together on this and sharing equipment and work so we can both feed our families. We are looking for some way to decrease our PH to about 6.5 or 7 would be good, because thats where our plants like. I grew some food in mine last year but it could have done better which sounds consistent with being outside the ideal PH range. I have heard of Aluminum sulfur or something like that and we really dont want to use that if its a chemical thats not natural. Also we looked into composting and that was to confusing and time intensive especially on our scale which we mostly do by hand and tractor but fixing tractors takes time and money, so we try to limit our use of those. Anyways we're a month away from planting which i know is not ideal but is there anything we can do to start the process of changing the PH but still be able to plant? Any idea will do. Oh i also heard about Manure tea and pine needles. And he has 50gallon drums and i have a few hundred feet of pine trees. So thats a option to if we need to. Let me know what you guys think, thank you!How can i decrease my gardens PH?
    I use aluminum sulphate, although you can acidify your soil with sulfur, oaks leaves, pine bark and needles, peat moss, and use of an acidified fertilizer, etc. Your local garden center can recommend the best thing to use. If you want to go strictly organic, peat moss is your best bet. Aluminum sulphate is being used for my blueberries. It has done a good job.How can i decrease my gardens PH?
    http://www.ipm.iastate.edu/ipm/hortnews/

    I read most of what you wrote here is an article for one state that talks about and shows a diagram to help you. Your best bet is to look up your areas extension from you local university. We have the University of Florida Extension Center that tells us almost everything we need to know, from what to plant when, and soil amendments to other details. Hope the link helps and good luck.
    Depending on what you want to grow, tomatoes require more PH than other plants.



    Click on the link below and you will find some good information!



    http://www.thegardenhelper.com/acidsoil.
    Some plants prefer acidic soils but most do better in a mid range. The best thing to help balance your levels is lime. It comes in several different forms, either powder (messy) or pelleted.



    I'd research out what levels you need for what plants, strike an average and apply garden lime as directed on the packages.



    We use a lot of leaf mulch which tends to be acid and we give almost everything a light sprinkle of the pelleted lime each spring. The pelleted stuff is more expensive but it is a lot less messy and usually requires fewer bags to do the same sq. footage so it balances out. I only needed one 40# bag of the pelleted vs. 4 bags of the powdered lime.
    http://www.google.com/search?q=is+garden



    http://www.bestnest.com/bestnest/RTProdu

    I want to get pregnant and have a boy.I heard it has to do a lot with my body's PH. How do I change it ?

    I read that in order to have a baby boy my PH needs to be more Alkaline. I also read that I need to check my urine for my Ph but it did not say how to make it more Alkaline to promote getting a baby boy. Any info will help!I want to get pregnant and have a boy.I heard it has to do a lot with my body's PH. How do I change it ?
    Some old Mexican man I knew swore that in order to have a boy the guy needs to ejacultate very deep inside you, if not you will have a girl. I know that sounds stupid, but he had 3 boys and 1 girl and swore by it. Good luck. Remember any healthy baby is a gift. Would be better to have a healthy girl than a jacked up boy.I want to get pregnant and have a boy.I heard it has to do a lot with my body's PH. How do I change it ?
    to get pregnant you need to have sex.



    you cannot chose the sex of your baby, it all depends on the males DNA
    Mang, the gender of your child has already been decided. If you're that determined to have a male, abort the f眉cker and learn how to splice DNA.
    Nope, actually all of that is incorrect.

    It's already been determined.

    It is determined by your husband's sperm.

    If they donate an X or a Y chromosome.. that determines the gender of the baby.

    X = girl

    Y = girl.



    sorry :(

    Adding a Strong Acid to a Buffer?

    A beaker with 140 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 4.10 mL of a 0.280 \it M \rm HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.Adding a Strong Acid to a Buffer?
    5.00 = 4.760 + log Acetate / acetic acid

    5.00 - 4.760=0.24

    10^0.24 = 1.74 = acetate / acetic acid



    1.74 acetic acid = acetate

    acetate = 0.100 - acetic acid



    1.74 acetic acid = 0.100 - acetic acid

    acetic acid = 0.0365 M

    acetate = 0.0635 M



    moles acetate = 0.140 L x 0.0635 = 0.00889

    moles acetic acid = 0.0365 x 0.140=0.00511



    moles H+ added = 4.10 x 10^-3 L x 0.280 M= 0.00115



    moles acetete = 0.00889 - 0.00115=0.00774

    moles acetic acid = 0.00511 + 0.00115=0.00626



    pH = 4.760 + log 0.00774/ 0.00626= 4.852

    How can I take the pH of a sulfide-containing solution?

    I'm interested in being able to take the pH of a solution using a pH probe. The solution contains a small quantity of free sulfide ions, which I'm told poison pH probes. I realize I could calculate the pH doing a titration, but for my purposes this can't be done.



    The best method I've come up with would be to add some reagent to selectively precipitate the sulfur without significantly changing the pH. As far as I can tell, barium chloride would be appropriate for this purpose, since BaS is insoluble and BaCl2 shouldn't affect the pH. I realize there are plenty of health hazards associated with barium compounds, (and sulfide compounds for that matter) but this is a theoretical experiment at this point. Would BaCl2 precipitate sulfides without affecting pH?



    Thanks in advance.How can I take the pH of a sulfide-containing solution?
    since sulfides are the conjugate bases of weak acids like H2S or HS- then they will contribute to pH by hydrolysis



    (increase pH) ....thus removing them intoto can reduce the pH and not be a meaningful measure of the actual pH. Use of the eletrodes containing Ag can indeed result in poisoning as Ag forms a quite insoluble sulfide. Have you thought about using pH test strips, like litmus, or ones that give a narrower pH range than litmus for the developed color , or if the solution is clear enough using a universal indicator for color endpoints of pH ? These are much simpler than titration and depending on what accuracy you need, may suffice and they are readily available and pretty inexpensive . Also, the calomel electrode is much less senstive to the sulfide than a silver based electrode.How can I take the pH of a sulfide-containing solution?
    try using an alternate method of calculating pH?

    litmus paper is more disposable than probes...
    You should be able to find a similar product. If you know the probable pH range then it is best to buy something that will help you measure it more correctly with a pH test strip. For better precision you will need a calibrated pH probe by Siemens, Fisher Scientific, Omega, Cole-Parmer, BDH, Honeywell, or any other local lab equipment supplier:



    http://www.cenmed.com/productDetail.asp?
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  • What are the contolled, independent, and dependent variables?

    what are the independent, dependent and controlled varible in this experiement.



    my paper says this:



    Indivdual organisms must maintain a relitvely stable internal enviroments. both organisms and cell respond to many evironmental factors that otherwise would change their internal enviroment.



    How do organisms maintain the pH of their tissues within a normal range despite activities that tend to change the pH? You begin to answer the question by comparing that response of a nonbiological material and a biological material to the addition of acid and a base. The nonbiological material is tap water and the biological material is one of severl species devrived from organisms.What are the contolled, independent, and dependent variables?
    independent: pH environment

    dependent:response of the material to the pH change

    controlled: tap water, species usedWhat are the contolled, independent, and dependent variables?
    when controlled,how can you have independence.you would only have dependence....right?

    Why do the fish in my tank keep dying?

    I have a 20 gallon freshwater tank for over a year now. The problem is, every time i add new fish they die. Usually, the fish hangs out in the corners of the tank and at the bottom, they don't swim around like they should. I have 1 male swordtail and 1 loach. They are the only fish that have survived for a descent amount of time. I believe that the amonia, nitrate, etc. levels are fine; however, I dont have a kit but I only have 2 fish and I keep up on partial water changes. The pH level is alkaline but it should be in range for the swordtails I do add and from what I understand, they are hardy fish. In addition, the plants that I have in my tank are surviving but their not really taking off like they should be. Is it possible that the pH is causing the problem? If it is how can I fix this? And other than pH, what else could be causing new fish to die in my tank and what can I do to keep these fish alive in the future? Any help would be much appreciated.Why do the fish in my tank keep dying?
    You say you do water changes, but do you do them every week like you are supposed to? Partial (25-30%) water changes, weekly, are the best thing you can do to keep your tank water healthy and your fish happy. Your two fish that are surviving may only be hanging on by a thread if you aren't doing regular partial water changes.



    You really should get an ammonia test kit. You can pick up a cheap one for about $3-4. Get the liquid (it is the cheapest) and IMHO the best way to check ammonia. The test strips get real expensive. However, if you are doing weekly partial water changes, there shouldn't be an ammonia problem.



    The main reason for new fish dying is the difference in the pH of the water from the store and your water at home. A difference of only .5 on the pH scale can put a new fish in pH shock. Sometimes they will make it, but most times they die.



    You should ask the fish store to test a sample of your water and a sample of their water so you can see how far off it is. I have taken as long as 4 hours to acclimate a new fish because of the differences in pH between the bag and my tank water.



    Email me if you have more questions, I will be glad to help.Why do the fish in my tank keep dying?
    Are you floating the fish before adding them to the tank? Leave them in their bags of water from the pet store and float them in the tank. After 2 hours, add a bit of tank water to their bags. Add more an hour later, etc. Then dump the fish in.



    Make sure the water isn't too cold or too warm.
    Have you done a water change lately?

    does any of your fish have diseases? ( ick, bactieral problems, ect.)

    good luck!
    do you have a filter?
    Dude,

    This is a very vague question.

    A lot of factors come onto play.

    Do they have adequate cover?

    Are they in extreme light?

    Are they in an area where they are easily disturbed?

    I could go on %26amp; on.

    Start with a hardy breed, goldfish, koi, etc.

    Move on from there.
    you are going to have to get the water tested to start. Another question for you, are you buying these fish that keep passing away from the same store? Unfortunately places like Walmart are noted for their fish not to be survivors. I would suggest another store for starters.



    PH does play an important roll on your fish, however even if your ph is a little higher or lower than the stores isn't going to kill them off right away. When you acclimate your fish to their new home they need to be done a certain way. Float your bag for appx. 15 minutes. Allow the water temps to become the same. Open the bag and add 1/4-1/2 cup of your tank water to the bag and let them sit another 10-15 minutes. Add another 1/4-1/2 cup of your water and sit again. One more time then you can release your fish. This will allow your fish to acclimate slowly from the stores water to yours. Remember only one or two fish at a time no new ones for a week or more. That way your biofilter will not get over loaded. PH can inhibit your plants growth, however that is only part of the entire problem



    Weekly water changes are a must for problem tanks, however if you don't know what the water quality is you are basically taking a shot in the dark.



    You are running an undergravel filter. Is this Only? No top filter? I have never been a fan of running strickly undergravel filters on a tank. This does not allow for proper dissolved oxygen to enter the tank (like a rear filter would do) This could be another problem. Your tank is not filtering out any chemicals or food particles, even if you are using a gravel siphone to clean the bottom, the nitrates can build to toxic levels. Especially if you are only running air hoses to the UG Filter.



    I would start with getting your water tested (and the tap water you are using to fill your tank, that way you have something to use as a base) to see exactly what you are working with. Keep up your weekly cleaning. Siphone the gravel and clean the tank. Remember to use your dechlor/water conditioner to the water prior to adding it to your tank.



    If you don't have a rear filter, get one. A whisper 20 is fairly inexpensive at walmart. (around 19.99).



    Be sure your heater and temperature setting is correct.



    Remember it is more important to have a stable PH than to have one that jumps all over the place.



    Do you have bogwoods or peats (from your plants) in the tank? I realize there is a lot to think about here and trying to narrow it down is difficult.



    Feel free to email me or repost with your water results and we can all help from there.

    Adding a strong acid to a buffer?

    A beaker with 175 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.1 M. A student adds 9.00 mL of a 0.410 \it M \rm HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.76.Adding a strong acid to a buffer?
    Let x = [acid]

    let y = [salt]

    x + y = 0.1



    5.00 = 4.76 + log y/x

    10^0.24 =1.74 =y/x



    x = y / 1.74



    y/1.74 + y = 0.1

    y + 1.74y = 0.174

    y = 0.0635 M

    x = 0.0365 M



    moles CH3COO- = 0.0635 x 0.175 L =0.0111

    moles CH3COOH = 0.0365 x 0.175 = 0.00639



    Moles H+ added = 0.009 L x 0.410 =0.00369

    CH3COO- + H+ %26gt;%26gt; CH3COOH

    moles CH3COOH = 0.00639 + 0.00369 =0.0101

    moles CH3COO- = 0.0111 - 0.00369 = 0.00741

    total volume = 175 + 9 = 184 mL = 0.184 L

    concentration acid = 0.0549 M

    concentration salt = 0.0403 M



    pH = 4.76 + log 0.0403 / 0.0549 = 4.63

    How does blood act like a buffer solution?

    Buffer solutions resist changes in pH, how does blood achieve this? why is there a need to maintain constant pH in the blood?



    (I know about the bicarbonate thing, so please go into further detail when answering)How does blood act like a buffer solution?
    since you know about the CO2/bicarbonate system, you can write out the equilibrium equation:

    CO2+H2O = HCO3(-) + H+

    Ka=[HCO3-]*[H+]/[CO2] (since the concentration of water is constant and doesn't change much, it's often included in Ka)



    so upon conversion you'll get that

    pH=pKa+log([CO2]/[HCO3-])

    Since CO2 and water are abundant in the blood, this system forms easily. Of course the presence of proteins and other substances also affects the pH of blood, but there are cellular mechanisms (inluding enzymes, carbonic anhydrase being one that guard the homeostasis) to keep it pretty much constantHow does blood act like a buffer solution?
    The pH of human blood must stay in a relatively narrow range around pH = 7.4 (7.35-7.45) in order to ensure cellular survival. It can be maintained within these limits thanks to buffer systems utilizing plasmatic carbonates, phosphates or proteins for example.



    The buffer ability of blood, in addition to its role in the metabolism, can also minimize the consequences of an accidental ingestion of acid (or base).

    How much water must be added?

    if you are given 100 ml of potassium hydroxide with a pH of 12.0 and want to change the pH to 11.0 by adding water, how much water do you add? please help, thank youHow much water must be added?
    a pH unit changes the concentration by 10 times



    to go 10 times weaker from pH12 to pH 11



    to dilute it 10X's....you must dilute the 100 ml KOH into 1000 ml



    your answer is that you must add 900 ml of waterHow much water must be added?
    ?

    How vulnerable are salmon fry to fluctuations in water quality caused by high/low conductivity ?

    Changes in pH, pollutants, road salt are contributing factors.How vulnerable are salmon fry to fluctuations in water quality caused by high/low conductivity ?
    they are very vulnerable to all the issues you have mentioned
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  • How does the human body sense changes in blood pH?

    I think this has something to do with homeostasis but I'm not really sure how the body senses it.How does the human body sense changes in blood pH?
    The decreased bicarbonate that distinguishes metabolic acidosis is therefore due to two separate processes: the buffer (from water and carbon dioxide) and additional renal generation. The buffer reactions are:





    The Henderson-Hasselbalch equation mathematically describes the relationship between blood pH and the components of the bicarbonate buffering system:







    Using Henry's Law, we can say that [CO2]=0.03xPaCO2

    (PaCO2 is the pressure of CO2 in arterial blood)

    Adding the other normal values, we get





    So the body senses the PH changes with changing the consentration



    and pressure of CO2 in the Blood



    I hope it be Helpful





    = 6.1 + 1.3

    = 7.4

    Tuesday, September 13, 2011

    Responses to pH?

    Can someone please help me answer these questions?



    1. How do biological materials (liver and potato) respond to changes in pH?

    2. How does water respond to changes in pH?Responses to pH?
    1. if the ph is to high(acidic ) then they dissolve abd when it is low (basic) they tend to not react



    2. water becomes acidic when its ph value is increased and becomes basic when its decreased

    Adding A Strong Acid to a Buffer Chemistry help needed!!!!!!!?

    A beaker with 120 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 4.00 mL of a 0.420 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.Adding A Strong Acid to a Buffer Chemistry help needed!!!!!!!?
    let x = [acetate]

    ley y = [acetic acid]



    x + y = 0.100

    5.00 = 4.760 + log x/y



    5.00 - 4.760=0.24 = log x/y

    10^0.24 =1.74 = x/y

    1.74 y = x



    1.74 x + x = 0.100

    x = 0.0365

    y = 0.0635



    moles acetate = 0.0635 x 0.120 L=0.00762

    moles acetic acid = 0.0365 x 0.120 L=0.00438



    moles H+ added = 4.00 x 10^-3 L x 0.420 M=0.00168



    CH3COO- + H+ = CH3COOH

    moles acetate = 0.00762 - 0.00168=0.00594

    moles acetic acid = 0.00438 + 0.00168=0.00606



    pH = 4.760 + log 0.00594/ 0.00606=4.75



    delta pH = 0.25

    How much baking soda/sodium bicarbonate in mg/liter to change water composition by pH 0.1 or any other amount?

    Trying to make water more alkalineHow much baking soda/sodium bicarbonate in mg/liter to change water composition by pH 0.1 or any other amount?
    If it is pure water, then the NaHCO3 would change the pH from 7.0 to 7.1. For 1 liter of water, you will need 0.1 moles of NaHCO3, or 8.4 g of NaHCO3.

    Which of the following best shows how primary structure relates to protein function?

    A. High temperatures cause proteins to denature.



    B. Changing one amino acid in the protein hemoglobin causes sickle-cell anemia.



    C. Proteins are sensitive to changes in pH.



    D. The shape and chemistry of an enzyme's active site determine its functionWhich of the following best shows how primary structure relates to protein function?
    B



    Changing one amino acid in hemoglobin results in a different protein structure under oxygen stress conditions which results in a deformed red blood cell (sickle-cell anemia).Which of the following best shows how primary structure relates to protein function?
    The answer is B.

    Primary structure is the specific amino acid sequence coded by DNA which makes up a protein. It is not how it folds or the shape of the structure.



    In sickle-cell anemia the normal sixth amino acid (Glu) is replaced by Val, which in turn changes the entire shape of the cell (hence the sickle shape). So therefore the shape change is due to an error in primary structure (the coded amino acid sequence).





    Explained wrong answers:





    It is not A because, while high temperatures DO cause the denaturization of proteins, this does not effect primary structure, it affects the shape. When it denatures the bonds (such as the weak Hydrogen bounds of secondary structure) the protein looses its specific shape and can no longer function, but if the conditions are returned to normal it will return to its specific shape because the primary structure was not effected. And primary structure determines the bonds since it determines the amino acid sequence.



    C is incorrect because pH changes, like temperature changes, can denature but only effect secondary, tertiary, and quaternary structure.



    D is incorrect because it is once again referring to shape. While the statement is true, it does not answer the question.









    Hope this helped / is very clear.
    b;

    Preparation of Culture Media?

    1.From what source do bacteria obtain their mineral elements like, Ca, Mg, Fe, etc. in nutrient broth? (agar is used as the medium)

    2.How can one remedy the effect of pH change due to sterilization?

    3. What is the difference between the sterilized and unsterilized media?

    4. Is there any effect of the pH to the keeping of unsterilized media?Preparation of Culture Media?
    1.

    There are two types of media.

    ';Synthetic'; and ';Complete';



    If synthetic

    Would have to add all the components using pure chemical stocks.



    If complete.

    Can use yeast extract which contains alot of compounds, minerals, vitamins, organics etc.

    A hydrolysate (bacto-peptone), often from milk.

    Also a good source of nutrients, amino acids



    2.

    The pH of the media should be adjusted to an optimal or near-optimal pH for the particular bacteria species.

    Bacteria such as E. coli grow best at a pH 7.2+/-0.4

    Lactobaccillus is on the acidic side.



    Yes, the pH of media will change typically by 0.3.

    If it is important to have an exact critical final pH.

    You can make an adjustment before autoclaving.

    Also don't autoclave anything longer than needed.

    Just long enough to kill any microbes and melt the agar.

    Can get undesirable chemical reactions.

    Esp. if it is acidic. Might hydrolyse sugars and the agar.



    If liquid medium, alternative is to filter sterilize.



    Sometimes pH buffers are added to the medium.

    Can be autoclaved separately and added to flask containing the medium.



    3.

    Sterilized vs. un- or nonsterilized medium.

    Sterilized will have less contaminating wild bacteria, yeasts and mold growing on it.



    4.

    Non-sterilized medium will eventually show obvious signs of mold etc. growing in it.

    If stored in the refrigerator, the cooler temperature will delay the growth of contaminants.

    Some contaminates grow better or suppressed at certain pH.
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  • How to distinguish between ethanoic acid and hydrochloric acid?

    What I thought of was adding thymol blue to an equal concentration and volume of both acids. In hydrochloric acid, thymol blue (changes at pH 3) should turn red but in ethanoic acid, it turns blue.



    Are there any other ways of distinguishing between the two acids?



    Thanks!How to distinguish between ethanoic acid and hydrochloric acid?
    1. If not too dilute, merely smell them...carefully if concentrated. Do you smell vinegar?...acetic acid.

    2. Run a chloride test. Add a few drops of AgNO3 soln...white ppt with HCl, no reaction with acetic acid.How to distinguish between ethanoic acid and hydrochloric acid?
    Ethanoic acid is acetic acid, in vinegar, so you could simply smell them! Your method is good, HCl will always be much more acidic at the same concentratio.!

    Can anyone explain this buffer solution question?

    The question is this:

    '; A buffer solution of acetic acid-sodium acetate has a pH of 7.00. Upon addition of an acid, 0.5 mmol of H+ was produced in the solution. What is the concentration of the buffer if the change in pH is less than 0.5? The initial volume of the buffer is 75.0 cm^3. ';



    Can anyone explain to me how to solve this? No need to solve. Just a clear explanation would be sufficient.Can anyone explain this buffer solution question?
    It's not a very good question. First of all, an acetic acid - sodium acetate buffer won't be much of a buffer with a pH of 7. The maximum buffering capacity will be when the amount of weak acid and it conjugate base are the same. If that is the case then pH = pKa. Since the Ka of acetic acid is 1.8 x 10^-5, then pKa = 4.74.



    A buffer is a mixture of a weak acid (HC2H3O2) and its conjugate base (C2H3O2^-). The action of a buffer can be explained with Le Chatelier's principle, and the pH of a buffer depends on the concentrations of the weak acid and the conjugate base, and the Ka of the weak acid. The pH of a buffer can be approximated using the Henderson-Hasselbalch equation.



    Secondly, you don't have a ';concentration of the buffer';. You have a concentration of H+, and a concentration of C2H3O2-, and a concentration of undissociated HC2H3O2. But there is no concentration of the buffer.



    Now I see why you are having a hard time with this question. I suspect that the writer of this question may not have firm grasp of buffer systems.

    Do you think it's safe to put flagstone in a goldfish tank?

    Hi,

    i was wondering if it's safe to put it and build it. its a 20 gallon goldfish aquarium! a few question!

    is it safe for the goldfish?

    will it put to much pressure on the glass? (it's about 70 pounds)

    how do i clean it fist

    and will it change the PH?Do you think it's safe to put flagstone in a goldfish tank?
    Hello Ddd I have taken some rocks from beside a railroad track I brushed them off under running water then I boiled them in a pot for a few minutes to get read of any harmful bacteria.

    IT well not put to much pressure on the glass if you don`t put it against the glass.Even if it did change it would not change it enough to do any harm.

    Goldfish are hard to keep alive,just look at all the sick goldfish on this web-site.I would get something els.Do you think it's safe to put flagstone in a goldfish tank?
    Well, it depends. If the stone is all natural and hasnt been cleaned with Muriatic acid then i would say yes go for it. There is no way to tell for sure that it is acid free.

    Do you think it's safe to put flagstone in a goldfish tank?

    Hi,

    i was wondering if it's safe to put it and build it. its a 20 gallon goldfish aquarium! a few question!

    is it safe for the goldfish?

    will it put to much pressure on the glass? (it's about 70 pounds)

    how do i clean it fist

    and will it change the PH?Do you think it's safe to put flagstone in a goldfish tank?
    Flag stone is fine and should not change your PH - if you do want to be sure though, pour vinegar on it - if it fizzes, this means it contains calcium carbonite and will raise the PH.



    If the stone could fit in the tank, the bottom glass can hold it provided you don't actually drop the stone and cause it to shatter (trust me, I've used TONS of rocks in some of my tanks) - but you don't want to be stressing the sides of the tank by leaning too much of that weight against the side of the tank.



    Sounds like an awfully big rock for a tank that needs as much water volume as you can get, to tell you the truth. It's just not worth it if your goldfish are left with only 10 gallons of water.



    However, it is safe to use otherwise and all you need to do is wash it in hot water. If you really want to play it safe you can bake the rock in the oven for half an hour to ensure anything potentially on it is killed - just make sure you cool it fully before using it. I've kept tons of rock-scaped setups for my rock dwelling cichlids and all I've ever done is rinse them in hot water.

    Will He Ever Change Or Am I Wasting My Time? How can Someone Who Claims They Love You So Much Do This?

    I posted last nite and got some great responses on how to approach the situation. I was told to dump him, but just couldnt do that part yet. This is what happened and how I handled it.. now what do i do next? My bf who cheated on me a yr ago had promised to cut off ALL ties with the girl but he wanted to do it gradually as he did not want to make enemies with her. (thats what he told me) Its been 5 months now and he still communicates with her knowing I feel uncomfortable. He recently changed his ph number and told me she didnt have the new number but i found out she does have it. He denied her having the number and still denies it. But then he claims he does talk to her ';once in a while'; and has cut down, its just that I dont see it. (thats what he says) I told him it doesnt take someone 5 months to do it and when he finally decides to do it we will have a better relationship. He thinks I am putting conditions on him and says he has cut down. I dont agree. see below plzWill He Ever Change Or Am I Wasting My Time? How can Someone Who Claims They Love You So Much Do This?
    Angel:

    Life is hard and yes, sometimes you have to walk away from things/people that serve to make life unpleasant.

    I know you love him; I've been where you are.

    BUT...somehow, you've gotta love yourself more than you love him.

    You've gotta love yourself, more than you love his drama in your life.

    Loose that man and let him go.

    While you're at it; loose yourself from him.

    He's not gonna stop hurting you.

    I don't know why people who have hurt us once/twice before, tend to do it again, but that is the way of the world!

    One thing I've determined in my 44 years is that you cannot let people go 'a little bit'; you have to quit some people COLD-TURKEY!

    When you let him go, DO NOT call him (lose his number(s), DO NOT accept his calls, and if he should happen to drop by, DO NOT let him in!

    I dated a guy once and everything was good until he started doing a lot of double-talk!

    He wasted my time in a big way.

    Yet, despite my urge to put a knife in his gut, I pulled away from him like he had a contagious disease!

    I'm glad I did, because (as I have recently determined) he ain't worth a napkin full of newly-blown boogers!

    I see him through a different set of eyes and my vision is 20/20!

    He aint' all that and I truly hate the fact that I gave him 2-seconds of my valuable time!

    Life will get better for you.

    You must maintain faith in God and faith in yourself!

    Once day...your prince will come; just make sure that all of the frogs in your life are floating downstream on another lily-pad!



    THE MIDDLEFINGER



    PS: WHEN he comes back (and they always do), keep this simple thought in mind: NEVER, EVER GET INTO THE HABIT OF TAKING A SH!T AND THEN STEPPING BACK IN IT!Will He Ever Change Or Am I Wasting My Time? How can Someone Who Claims They Love You So Much Do This?
    You can only get walked on if you lay down. If this guy really did love you he a) would have not cheated on you in the first place b) he would have cut ties with the other girl right away. The only girl he should care about is you. It sounds like he is full of excuses and he cuts you down and says you are putting conditions on him because he knows he is wrong and he is trying to take the focus off of him and put on you. You are allowing this to happen and you need to think about yourself and your needs. Do you really want to be upset over some guy that doesn't really care about but says he does; actions speak louder then words. I know how hard it is but you can either be sad while you are getting over him, get over him and meet a great new guy (yes, it will take time) or you can stay sad and with him until he breaks up with you. I know this is hard.. Good luck!
    I would completely cut him off. It seems like talking to her is more important to him than your relationship. Why would he be concerned with not making enemies with her? He should more concerned with making things right with you and how still talking to her makes you feel. You deserve better!
    you obviously like this man a lot? but if he is still seeing this girl on purpose then he obviously cnt care that much about you.. you need to accept that he might not be the right person for you and try to move on.
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  • By what factor does [OH- ] change when the pH increases by 3.6?

    WEBASSIGN HELP! I have no idea how to do this...By what factor does [OH- ] change when the pH increases by 3.6?
    By a factor of about 4000.



    pH is a logarithmic base 10 scale, that means that for every change of 1 point the amount of the stuff you're measuring (hydrogen/hydroxide ions) changes by a factor of 10.



    A change of 3 points therefor means there is a 1000x difference, and a shortcut for working with base 10 logarithms is that every change of .3 slightly less than doubles it. You can use a calculator to get more specific: 3981xBy what factor does [OH- ] change when the pH increases by 3.6?
    pH +pOH=14



    this means that if pH goes up by 3.6



    each pH unit of change is a factor of 10, so



    10 X 10 X 10 X 3.98107



    So [OH-] change by a factor of 3981.07 thousand



    so the pH will be pH 7 + 3.6 = 10.6

    Adding a strong acid to a buffer?

    A beaker with 180 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M . A student adds 5.80 mL of a 0.490 M solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.Adding a strong acid to a buffer?
    Well, I'm bad at Chemistry but I can do a partial, concept answer.



    A buffer is a chemical which stabilizes pH, so whether acid or base is added, the pH will tend to bend towards the original value.



    Sorry, I can't complete the question.



    An example of a buffer:



    In order to stabilize the pH in blood, the body has an organic buffer of H[2]CO[3], which can decompose into HCO[3]- and H+ in response to a drop in pH and can recompose to H[2]CO[3] for a rise in pH. Since pH is a measure of the proton concentration (H+), the addition or removal of H+ changes the pH.Adding a strong acid to a buffer?
    huh?

    How to use PH-minus treatment for a new aquarium?

    Used 10ml the first time(for the 30l aquarium)! with no change in the

    PH level.After 24 hours the level has not changed.Used 10ml more and still no change.the level I got is 6.0.

    Any suggestiones please?



    Thank YouHow to use PH-minus treatment for a new aquarium?
    Your ph is going to be what your ph is. Fish can and do live in a wide range of PH. 6 isn't that bad and doesn't warrant using ph modifiers.



    Having a ph that is stable is better than one that constantly changes. Your ph perhaps isn't changing due to two reasons, your carbon is pulling it out as fast as you put it in and/or you have decorative wood or gravel that is lowering your PH.



    Test your supply water. See what the PH is. If your supply water is 6 your ph will be 6.



    If you are having concerns with the PH at that level you can add items like seashells (hidden in the filter). These shells will slowly in crease your PH in the tank and keep it at a specific level without you having to test it daily and adjust it daily.



    Although drift woods in tanks are nice additions, some will decrease the ph in the tank. Alternatives to this are adding the items like shells hidden in the filter.



    How to use PH-minus treatment for a new aquarium?
    Well I think you need to have pH plus. 6.0 is very acidic. Good Luck!
    ph up, ph down, and similar chemicals are bad news. I recommend that you NOT use them.
    THE PH OF A TANK NEEDS TO BE 7!
    Why do you want to lower your pH from 6? What kind of fish do you have? Most of the pH altering chemicals are useless. If you want to lower your pH put some bogwood in the water. If you want to raise it something like sea rock or coral gravel will do the trick

    How does the pH of sodium hydrogen carbonate solution change when exposed to carbon dioxide?

    I've heard that dissolving 0.429g solid sodium hydrogen carbonate in 500ml water can be used to test for carbon dioxide levels in the air, as the pH of the solution changes when exposed to CO2. Is this true, and if so, how? Any help much appreciated.How does the pH of sodium hydrogen carbonate solution change when exposed to carbon dioxide?
    the pH will lower but there will be no titration just an increase in H3O+ ions and subsequently lower

    pHHow does the pH of sodium hydrogen carbonate solution change when exposed to carbon dioxide?
    titration occurs I wish I could go further into detail but my chem class is terribly hard

    HOW TO CHANGE MY POND PH LOWER?

    HOW DO I MAKE MY POND PH LOWER FROM 8 TO 7 ?

    I HAVE 10 KOIS AND 20 GOLDFISH.

    MY TAP WATER IS 8.5HOW TO CHANGE MY POND PH LOWER?
    You can buy a PH buffer from your local aquarist shop which will either lower your ph or set it to a certain PH which is best for your goldfish and koi,i have a reef tank and i use waterlifes 8.3 buffer works well and im sure they sell one for ponds, its not to expensive either and is just like a type of powder you dissolve into usually a pint of pond water.



    Try these websites:



    http://www.waterlife.co.uk/waterlife/72buffer.htm



    http://www.ntlabs.co.uk/product_details.php?product_id=31HOW TO CHANGE MY POND PH LOWER?
    Try adding some natural lemon juice. I am not sure about the how the health of fish will affect.
    You should fill your pond and let the water set a day or two and do nothing to change your ph .The ph will go down on its own after a few days with the fish excreations I hope you have atleast a 300 gal pond for the number of fish you are putting in it other wise you are way over crowded and most certainly your fish will start dying due to high nitrate and amonia levels.

    How can I figure out the parent acid or base of a salt?

    Below is the actual question I need answered, but I also want to know how to figure out what is the parent acid or base of any compound.



    Each of the following compounds are dissolved in pure water. Which will change the pH of the resulting solution? List all that apply.

    MgF2

    KHCO3

    KCN

    NaCl

    MgCl2How can I figure out the parent acid or base of a salt?
    You use ACID + BASE = SALT + WATER



    Look at formula .. first bit [metal] relates to base eg MgF2 ... base Mg(OH)2



    Second part relates to acid .. basically H in front eg HF, HCN, H2CO3 etc



    Only salts of strong acids and strong bases don't affect pH eg NaCl in this set.
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  • Approximately, how much kg of soil is in one square yard?

    i need to know how much hydrated lime should be used to change the ph of 3kg of loam soil by 1 level. --%26gt; Add 8 ounces of hydrated lime per square yard in loamy soils



    and...

    i need to know too how much aluminum sulfate must be used in 3kg soil if 1 square feet would need 2.4 ounces to change the ph level of 1 square feet of loamy soil by 1 level.Approximately, how much kg of soil is in one square yard?
    There are exactly no Kgs in 1sq yd of soil. To get mass you must have volume. (3 dimensions) you are describing surface.



    In your case, assume that the Lime will treat one ';square'; yard about 3 inches deep. or .0833yd X 1 x 1 = .0833 cubic yds.



    Top soil weighs between 2000 to 2700 lbs per cubic yd, depending on compaction and composition....so .0833 x 2500 =208 lbs +/-



    208 lbs = 94 kilograms. I deduce that you apply .085 ounce per kilo, so 3 x .085 = .25 oz, or add 1/4 ounce to your 3 kilos and mix well.



    Use a ph meter or test kit from the garden shop to test the final product. It takes a period of time for the chemical reaction (process) to complete. Slightly moist soil mixed or turned completely 3 or 4 times in a week should amend the ph. Give it a try.



    Al Sulfate , again, assuming 3 inchs deep x1ft x1ft = 0.25 cubic foot. 1 cubic foot of soil is about 35 to 40 kilos ....so 0.18 ounce to your 3 kilo of soil. Again mix well and allow sufficient time for the chemical reaction to amend the soil. Moisture and heat accelerate the process. Good Luck.