Answer to Question #63744 in General Chemistry for cl

Question

Calculate the pH change when 10. mL of 3.0 M HCl are added to 500. mL of the following A ) pure water B) aqueous solution of 3.0g of formic acid C) aqueous solution of 4.0g potassium formate D) aqueous solution containing 3.0 g of formic acid and 4.0 g of potassium formate.

Answer to each should consist of pH of each and the final pH after addition of HCl in order to find the CHANGE in pH. I have answered what i can:

a) pure water: pH 7 final pH : 1.22 change= -5.78

b) formic acid : pH 2.32 ?? final pH (dictated by stronger acid so) : 1.22 change: = -1.1

c) potassium formate: pH 8.87?? final pH: 3.5 ??? change: -5.37 ??

d) buffer: pH 3.61 ??? dont really understand this part.

ANY HELP GREATLY APPRECIATED