Question

What is the mass of nitrogen in a 50.0 g sample of sodium nitrite $\left(NaN{O}_2\right)$?

• A. 20.2 g
• B. 16.4 g
• C. 10.1 g
• D. 8.23 g
• E. 23.4 g

Answer 1

Answer: (C)

10.1 g

Molecular weight of $NaN{O}_2$ is $[23+14+(16\ast 2\left)\right]$, that is $69grams$

Amount of Nitrogen present in $69grams$ of $NaN{O}_2$ is $14grams$.

$69$ grams of $NaN{O}_2$ contain $14$ grams of $N$

$1$ gram of $NaN{O}_2$ contains $\frac{14}{69}$ grams of $N$

Thus, $50$ grams of $NaN{O}_2$ will contain $\frac{14}{69}$$\ast$$50$ grams of $N$, that is $10.1$ grams.

Option C is the correct answer.