Answer
$0.10mol$ $NaCH_3COO$ would form a buffer with 1L of $0.20M$ $ CH_3COOH$.
Work Step by Step
1. Try to identify a weak acid-base conjugate pair.
- $CH_3COOH$ and $CH_3COO^-$.
2. Now, analyze, and determine if the base/acid ratio is between 0.1 and 10:
Base: $0.10$ moles
Acid: $1L$ of $0.20M = 0.20$ $moles$
$\frac{0.10}{0.20} = 0.5$: Correct.
