Answer
$0.0100M$ $CaCl_2$ is more acidic.
Work Step by Step
1. Identify the conjugate pair of each ion:
First solution:
- $Na^+ : NaOH$: Strong base.
- $CN^- : HCN$: Weak acid.
Second solution:
- $Ca^{2+}: Ca(OH)_2$: Strong base.
- $Cl^-$: $HCl$: Strong acid.
2. Therefore:
- The first solution is basic (weak).
- The second solution is neutral.
3. So, the more acidic one is the second: $CaCl_2$
