Answer
$0.10M$ $KHSO_4$ is more acidic.
Work Step by Step
** You can find the $K_a$ values on table: 14.2 (Page 624)
Since both solutions have the same concentration, we just have to determine which compound is more acidic:
-$HF$:
$HF$ is an acid with $K_a = 6.8 \times 10^{-4}$
- $KHSO_4$:
It is a salt formed by $K^+$ and ${HSO_4}^-$.
$K^+$ has negligible acidity, so, we don't need to consider it.
${HSO_4}^-$ is an acid with $K_a = 1.1 \times 10^{-2}$
$HS{O_4}^-$ has a greater $K_a$ value, therefore, it is more acidic.
So, $0.10M$ $KHS{O_4}$ is more acidic.
