Question

For the reaction, $N_2+3H_2\to 2N{H}_3$. The rate of change of concentration for hydrogen is $0.3\times {10}^{-4}M{s}^{-1}$. The rate of change of concentration ammonia is:

• A. $-0.2\times {10}^{-4}$
• B. $0.2\times {10}^{-4}$
• C. $1\times {10}^{-4}$
• D. $0.3\times {10}^{-4}$

Answer 1

The correct option is A $-0.2\times {10}^{-4}$

$N_2+3H_2\to 2N{H}_3$

$-\frac{d\left[H_2\right]}{dt}=0.3\times {10}^{-4}M{s}^{-1}$

Rate $=\frac{1}{3}\frac{-d\left[H_2\right]}{dt}=+\frac{1}{2}\frac{d\left[N{H}_3\right]}{dt}$

$=\frac{d\left[N{H}_3\right]}{dt}=\frac{2}{3}\frac{-d\left[H_2\right]}{dt}$

$=\frac{d\left[N{H}_3\right]}{dt}=\frac{-2}{3}\times (0.3\times {10}^{-4})$

$\frac{d\left[N{H}_3\right]}{dt}=-0.2\times {10}^{-4}M{s}^{-1}$

Option $A$ is correct.