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Buffers

A chemist needs 250 mL of an acetate buffer with a pH of 5.12. The buffer solution has to be able to hold the pH to within plus or minus 0.10 pH unit of 5.12 even if 0.01 mol of NaOH or HCl enters the solution.

(a) What is the minimum number of grams of acetic acid and of sodium acetate dihydrate that must be used to prepare this buffer? (Neglect the volumes of NaOH and HCl)
(b) Describe this buffer by giving its molarity in acetic acid and its molarity in sodium acetate

Reply 1

charco

Study Forum Helper

Which part of the question are you having difficulty with?

Reply 2

Wangers

How can you neglect the volumes - the molarity of the soln depends on the volume - it is critical. To point you in the right direction - use the Henderson Hasselbach equation.

The simplification given at A Level is usually

ka* log([base]/[H+]