this is a sulubility question?

Question

This a problem of solubility
You need to produce a buffer solution that is = 5.37 . You already have a solution that contains 10 millimoles of acetic acid. How many of solid sodium acetate will you need to add to this solution? The of acetic acid is 4.74

Answer 1

Actually it is not a solubility problem, but a buffer.

Let's use the Henderson-Hasselbalch equation for simplicity

pH=pKa+log[CH3COONa]/[CH3COOH]

If V is the volume of the solution in L then
[CH3COOH]= mole/V= 0.010/V
[CH3COONa]= mole/V =x/V

so substitute in the equation and you get

5.37=4.74+ log((x/V)/(0.01/V))=>
0.63=log(x/0.01) =>
x/0.01= 10^0.63 =>
x =0.01*10^0.63= 0.0427 mole =42.7 mmole or since MW=82
m= 0.0427*82= 3.50 g