Question

In the synthesis of ammonia by Haber's process, if $60$ moles of ammonia is obtained in one hour, then the rate of disappearance of nitrogen is:

• A. $\text{30 mol/min}$
• B. $\text{6 mol/min}$
• C. $\text{0}\text{.5 mol/min}$
• D. $\text{60 mol/min}$

Answer 1

Answer: (C)

In Haber's process, ammonia is synthesized as

${\text{N}}_2+3{\text{H}}_2\frac{\text{F}\text{e},\text{M}\text{o},300\text{℃}}{\text{H}\text{i}\text{g}\text{h}\text{P}\text{r}\text{e}\text{s}\text{s}\text{u}\text{r}\text{e}}\to 2\text{N}{\text{H}}_3$

Rate of synthesis of ammonia = $\frac{60}{60}$

$=\text{1 mol/min}$

$\therefore$ Rate of disappearance of nitrogen, i.e.,

$\frac{-\text{d}[{\text{N}}_2]}{\text{d}\text{t}}=\frac{1}{2}\frac{\text{d}[\text{N}{\text{H}}_3]}{\text{d}\text{t}}$

$=\text{0}\text{.5 mol/min}$