Question

$50.0kg$ of $N_{2(g)}$ and $10.0kg$ of $H_{2(g)}$ are mixed to produce $N{H}_{3(g)}$. Identify the limiting reagent in the production of $N{H}_3$ in this situation.

• A. Nitrogen
• B. Hydrogen
• C. Can not be predicted
• D. None of these

Answer 1

Answer: (B)

The balanced chemical reaction is $N_2+3H_2\rightleftharpoons 2N{H}_3$ From the above balanced equation, $1mol$ of $N_{2(g)}$ reacts with 3 moles of $H_{2(g)}$.
$\therefore$ Moles of $N_2=\frac{50,000g}{28gmo{l}^{-1}}=1785.71mol$
or, Moles of $H_2=\frac{10,000g}{2.106gmo{l}^{-1}}=4960.3mol$
$\therefore 1785.7mol$ of $N_2$ react with $3\times 1785.7mol=5357.1mol$
but we have $4960.3mol$ of $H_2$ only.
Therefore, $H_2$ is a limiting reagent.