A buffer solution of pH = 5.15 is to be prepared from acetic acid (Ka = #1.80 x 10^-5#), sodium acetate and water. What must be the molar ratio of acetate ion to acetic acid in this solution to obtain this pH?
Ethanoic acid is a weak acid which dissociates:
The expression for
So the molar ratio of acetate ion to acetic acid is:
The ratio of conentrations which I have given also corresponds to the molar ratio since the volume is common to both.
We are told that the