Help with ap chem lab 19: pH properties of Buffer solutions?

Calculate the pH change when 1 mL of 0.2 M HCl is added to 50 mL of deionized water. How does this pH value change compare to those obtained when 1 mL of 0.2 M HCl is added to the buffers?





At what point did each of the buffers lose their effectiveness? ExplainHelp with ap chem lab 19: pH properties of Buffer solutions?
1 mL of 0.2 M HCl is added to 50 mL of deionized water:



0.001 litres @ 0.2mol/litre = 0.0002 moles HCl



0.0002 moles HCl / 0.051 litrers = 0.0039 Molar



0.0039 Molar H+ =



pH of 2.4



that's a drastic change in pH from deionized water of about 7.0

==========================



when the same amount of HCl is added to a buffer the pH hardly drops at all, be cause the conjugate base of the buffer mix removes the added H+ ... combining with it in an equilibrium shift making a weak conjugate acid of that base



I don't have your lab exp, but this is what typpically happens