Question

What is the pH of a 0.500 M solution of acetylsalicylic acid, pK 3.52?

Answer 1

`sf(1.91)`

Explanation:

For a weak acid:

`sf(pH=1/2(pK_a-loga))`

Where `sf(a)` is the concentration of the acid.

`:.` `sf(pH=1/2[3.52-log(0.5)]`

`sf(pH=1/2[3.52-(-0.301)]=1.91)`