PH Acids and Bases, HELP please :)?

Its not really basic pH but not too complex, but i dont get it anyway lol :/ Heres a few sample problems i dont understand. Like i dont know how to get the answer.



What is the change in concentration of H+ions when the pH of a solution descreases from 3 to 1?



The cincentration of H+ ions ina solution is 3.14x10^-4. The pH os this soution is 3.5. What is the pH of a solution whose concentration of H+ ions is 3.14x10^-2?



The concentration of H+ ions changes from 2.78x10^-5 to 2.78x10^-2. What is the change in pH of this solution?



The cocnentration of OH^-1 ions in some solutions is [OH^-1(aq)] = 1.0x10^-3 M (mol L^-1). What is the pH of theis solution?



These are just some i need help with, i need to know how to solve it, thanksPH Acids and Bases, HELP please :)?
pH = 3 =%26gt; [H+] = 0.001 M

pH = 1 =%26gt; [H+] = 0.1 M

change [H+] = 0.1 - 0.001 = 0.099 M



pH = - log 3.14 x 10^-2 =1.5



3 units



pOH = - log 1.0 x 10^-3 = 3

pH = 14 - 3 = 11PH Acids and Bases, HELP please :)?
pH is the negative log of the hydrogen ion concentration, so a one unit change in pH equals a tenfold change in the hydrogen ion concentration. For example a drop from pH 7 to pH 5 would be going from [H+] of 10^-7 to [H+] of 10^-5, a hundred fold increase.