Question

How many liters of $H_2$ can be produced at STP by the decomposition of $3$ mol ${NH}_3$?

• A. $4.5$ L
• B. $27$ L
• C. $67.2$ L
• D. $96$ L
• E. $101$ L

Answer 1

The correct option is E $101$ L

$2N{H}_3\to N_2+3H_2$
The decomposition of 2 moles of ammonia produces 3 moles of hydrogen.
The decomposition of 3 moles of ammonia produces $\frac{3\times 3}{2}=4.5$ moles of hydrogen.
At STP, 1 mole of any gas occupies a volume of 22.4 L. Hence, 4.5 moles of hydrogen at STP will occupy a volume of $4.5\times 22.4=101$ L.
Hence, 101 liters of $H_2$ can be produced at STP by the decomposition of 3 moles of $N{H}_3$.