# You are asked to make a buffer solution with a pH of 2.0. Use the information below to identify an appropriate choice of an acid and a conjugate base to make the buffer?

## You are asked to make a buffer solution with a pH of 2.0. Use the information below to identify an appropriate choice of an acid and a conjugate base to make the buffer. Specify both the acid and the conjugate base you would use. (Hint: There may be more than one right answer to this problem.)

Oct 22, 2016

There is no simple answer to this question.

#### Explanation:

It is tempting to say that we should use a chlorous acid buffer, because the $\text{p"K_"a}$ of ${\text{HClO}}_{2}$ is close to the desired pH of the buffer.

We could then use the Henderson-Hasselbalch equation to calculate the required ratio of the acid to its conjugate base.

However, the predictions of the Henderson-Hasselbalch equation can deviate significantly from the actual values when $\text{p"K_"a} < 3$.

We would have to do exact calculations using the simultaneous equilibria involved.

That is probably beyond the scope of this question.