Question

In a catalytic conversion of $ N_2 $ to $NH_3 $ by Haber s process, the rate of reaction expressed as change in the concentration of ammonia per unit time is $ 40 \times 10^{-3} $ mole $L^{-1} s^{-1.}$ If there are no side reactions, the rate of the reaction expressed in terms of hydrogen is

• A. $60 \times 10^{-3} mol \,L ^{-1} s ^{-1}$
• B. $20 \times 10^{-3} mol \,L ^{-1} s ^{-1}$
• C. $1200\, mol\, L ^{-1} s ^{-1}$
• D. $10.3 \times 10^{-3} \,mol\, L ^{-1} s ^{-1}$

Answer 1

Answer: (A)

$N _{2}+3 H _{2} \rightarrow 2 NH _{3}$
Rate $=\frac{1}{3} \frac{d\left[ H _{2}\right]}{d t}=\frac{1}{2} \frac{d\left[ NH _{3}\right]}{d t}$
$\Rightarrow \frac{d\left[ H _{2}\right]}{d t}=\frac{3}{2} 40 \times 10^{-3}$
$=60 \times 10^{-3} mol L ^{-1} s ^{-1}$