Calculate the pH of a buffer solution made by mixing 300 mL of 0.2 M acetic acid, CH3COOH, and 200 mL of 0.3 M of its salt sodium acetate, CH3COONa, to make 500 mL of solution. Ka for CH3COOH = 1.76×10–5

Approximately .

Step-by-step explanation:

Remark: this approach make use of the fact that in the original solution, the concentration of   and are equal.

Since is a salt soluble in water. Once in water, it would readily ionize to give and ions.

Assume that the and ions in this solution did not disintegrate at all. The solution would contain:

of , and

of from of .

Accordingly, the concentration of and would be:

.

.

In other words, in this buffer solution, the initial concentration of the weak acid is the same as that of its conjugate base, .

Hence, once in equilibrium, the of this buffer solution would be the same as the of .

Calculate the of from its :

.

the answer is the third / last answer

step-by-step explanation: