Buffer Capacity Practice Test

A student compares two buffers and then adds the same small amount of strong base to each.

Buffer A: $\text{HNO}_2/\text{NO}_2^-$ with $0.40,\text{M}$ $\text{HNO}_2$ and $0.40,\text{M}$ $\text{NaNO}_2$.

Buffer B: $\text{HNO}_2/\text{NO}_2^-$ with $0.10,\text{M}$ $\text{HNO}_2$ and $0.70,\text{M}$ $\text{NaNO}_2$.

Which buffer will show the smaller pH change?

A student prepares two buffers from different conjugate pairs.

Buffer A: $\text{HSO}_3^- / \text{SO}_3^{2-}$ with $0.15,\text{M}$ $\text{HSO}_3^-$ and $0.15,\text{M}$ $\text{SO}_3^{2-}$.

Buffer B: $\text{H}_2\text{PO}_4^- / \text{HPO}_4^{2-}$ with $0.30,\text{M}$ $\text{H}_2\text{PO}_4^-$ and $0.30,\text{M}$ $\text{HPO}_4^{2-}$.

The same small amount of strong acid is added to each buffer. Which buffer has greater capacity to resist the pH change?