Question

part a
what is the mass percent of na in sodium chloride?
39.3
47.5
60.7
58.4
none of the above

Explanation:

Step1: Find molar masses

Molar mass of Na: $22.99\ \text{g/mol}$, Cl: $35.45\ \text{g/mol}$. Molar mass of NaCl: $22.99 + 35.45 = 58.44\ \text{g/mol}$.

Step2: Calculate mass percent

Mass percent of Na: $\frac{22.99}{58.44} \times 100 \approx 39.3\%$.

Answer:

A. 39.3