Question

Nitric acid contains approximately what percent hydrogen by mass?

• A. $2$%
• B. $5$%
• C. $7$%
• D. $10$%
• E. $20$%

Answer 1

The correct option is A $2$%

Molecular weight of $HN{O}_3$ is 63 grams.

It contains 1 gram of Hydrogen in it.

Thus, mass percent of Hydrogen present in it is $\frac{1}{63}$ $\ast$ $100$, which is equal to 1.6 %

Thus, approximately, 2 % of Hydrogen is present by mass.

Option A is the correct answer.