Question

In the formation of sulphur trioxide by the contact process $2S{O}_2\left(g\right)+O_2\left(g\right)\to 2S{O}_3\left(g\right)$ The rate of reaction is expressed as
$-\frac{d\left(O_2\right)}{dt}=2.5\times {10}^{-4}mol{L}^{-1}se{c}^{-1}$
The rate of disappearance of $\left(S{O}_2\right)$ will be:

• A. $5\times {10}^{-4}mol{L}^{-1}{S}^{{}_1}$
• B. $-2.25\times {10}^{-4}mol{L}^{-1}{S}^{{}_1}$
• C. $3.75\times {10}^{-4}mol{L}^{-1}{S}^{{}_1}$
• D. $50.0\times {10}^{-4}mol{L}^{-1}{S}^{{}_1}$

Answer 1

Answer: (A)

$5\times {10}^{-4}mol{L}^{-1}{S}^{{}_1}$

From the reaction, Rate can be expressed as,

$-\frac{d\left[O_2\right]}{dt}$ =$-\frac{1}{2}\frac{d\left[S{O}_2\right]}{dt}$

Rate of disappearance of $\left(S{O}_2\right)$ is $2\times 2.5\times {10}^{-4}$ = $5\times {10}^{-4}mol{L}^{-1}{sec}^{-1}$