Question

For the reaction $N_2+3H_2\to 2N{H}_3$, how are the rate of reaction expressions inter-related $\frac{d[H_2]}{dt}$ and $\frac{d[N{H}_3]}{dt}$ ?

• A. $-\frac{1}{3}\frac{d\left[H_2\right]}{dt}=+\frac{1}{2}\frac{d\left[N{H}_3\right]}{dt}$
• B. $-\frac{1}{2}\frac{d\left[H_2\right]}{dt}=+\frac{1}{3}\frac{d\left[N{H}_3\right]}{dt}$
• C. $+\frac{1}{2}\frac{d\left[H_2\right]}{dt}=-\frac{1}{3}\frac{d\left[N{H}_3\right]}{dt}$
• D. $+\frac{1}{3}\frac{d\left[H_2\right]}{dt}=-\frac{1}{2}\frac{d\left[N{H}_3\right]}{dt}$

Answer 1

Answer: (A)

Rate Law is an experimentally determined equation of the rate of the reaction is called the rate law of the reaction. In rate law, the rate of the reaction is expressed as a function of the concentration of the reactants and products present in the reaction.
For this reaction, the rate of reaction is written as:-
$-\frac{d\left[N_2\right]}{dt}=-\frac{1d\left[H_2\right]}{3dt}$
$=+\frac{1d\left[N{H}_3\right]}{2dt}$