Question

percent composition and molecular formula
quiz complete
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what is the percent by mass of sodium in $na_2so_4$?
use %element$=\frac{\text{total mass of element in compound}}{\text{molar mass of compound}} \times 100$
16.18%
22.58%
32.37%
45.98%

Explanation:

Step2: Calculate total mass of Na

Total Na mass = $2\times22.99 = 45.98$ g/mol

Step3: Compute percent by mass

$\text{Percent Na} = \frac{45.98}{142.05} \times 100 \approx 22.58\%$

Answer:

Step2: Calculate total mass of Na

Total Na mass = $2\times22.99 = 45.98$ g/mol

Step3: Compute percent by mass

$\text{Percent Na} = \frac{45.98}{142.05} \times 100 \approx 22.58\%$