Question

For the chemical reaction $N_{2(g)}+3 H_{2(g)} \rightleftharpoons 2 N_{3(g)}$ the correct option is:

• A. $-\frac{d\left[N_{2}\right]}{dt}=\frac{1}{2}\frac{d\left[NH_{3}\right]}{dt}$
• B. $3\frac{d\left[H_{2}\right]}{dt}=2\frac{d\left[NH_{3}\right]}{dt}$
• C. $-\frac{1}{3}\frac{d\left[H_{2}\right]}{dt}=2\frac{d\left[NH_{3}\right]}{dt}$
• D. $-\frac{d\left[N_{2}\right]}{dt}=2\frac{d\left[NH_{3}\right]}{dt}$

Answer 1

Answer: (A)

$N _{2}+3 H _{2} \rightleftharpoons 2 NH _{3}$
Rate of reaction is given as
$-\frac{d\left[N_{2}\right]}{d t}=-\frac{1}{3} \frac{d\left[H_{2}\right]}{d t}=+\frac{1}{2} \frac{d\left[N H H_{3}\right]}{d t}$