Question

In the formation of sulphur trioxide by contact process,$2S{O}_2+O_2\rightleftharpoons 2S{O}_3,$the rate of reaction was measured as$\frac{-d\left[O_2\right]}{dt}=2.5\times {10}^{-4}molli{t}^{-1}se{c}^{-1}.$the rate of reaction expressed in terms of $S{O}_3$ will be :

• A. $-1.25{\times }^{-4}mol{L}^{-2}se{c}^{-1}$
• B. $50\times {10}^{-4}mol{L}^{-1}se{c}^{-1}$
• C. $-3.75\times {10}^{-4}mol{L}^{-1}se{c}^{-1}$
• D. $5.00\times {10}^{-4}mol{L}^{-1}se{c}^{-1}$

Answer 1

The correct option is D $5.00\times {10}^{-4}mol{L}^{-1}se{c}^{-1}$

$\frac{-d\left[O_2\right]}{dt}=\frac{1}{2}\frac{d\left[S{O}_3\right]}{dt}$
$\frac{d\left[S{O}_3\right]}{dt}=2\times 2.5\times {10}^{-4}=5\times {10}^{-4}mol{L}^{-1}se{c}^{-1}$