Question

In a reaction involving the synthesis of ammonia by Haber's process,
$N_2+3H_2\rightleftharpoons 2N{H}_3,therateofreactionwasmeasuredas=2.5\times {10}^{-4}mol{L}^{-1}{S}^{-1}$.
The rate of change of conc. of $H_2$ will be :

• A. $1.25\times {10}^{-4}mol{L}^{-1}{S}^{-1}$
• B. $2.50\times {10}^{-4}mol{L}^{-1}{S}^{-1}$
• C. $7.5\times {10}^{-4}mol{L}^{-1}{S}^{-1}$
• D. $5.0\times {10}^{-4}mol{L}^{-1}{S}^{-1}$

Answer 1

The correct option is C $7.5\times {10}^{-4}mol{L}^{-1}{S}^{-1}$

$r=\frac{-1}{3}\frac{d\left[H_2\right]}{dt}$
$\frac{-d\left[H_2\right]}{dt}=3\times 2.5\times {10}^{-4}=7.5\times {10}^{-4}mol{L}^{-1}{S}^{-1}$