Question

The reaction,$2SO_{2(g)} + O_{2(g)} \leftrightharpoons 2SO_{3(g)}$ is carried out in a $1\, dm^3$ vessel and $2 \,dm^3$ vessel separately. The ratio of the reaction velocities will be :

• A. 4 : 1
• B. 8 : 1
• C. 1 : 8
• D. 1 : 4

Answer 1

Answer: (B)

$2 \mathrm{SO}_{2}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{SO}_{3}(\mathrm{~g})$

For this reaction, rate

$\mathrm{r}_{1}=\mathrm{k}\left[\mathrm{SO}_{2}\right]^{2}\left[\mathrm{O}_{2}\right]$

On doubling the volume of vessel, concentration would be half.

Hence, Rate$\left(\mathrm{r}_{2}\right)=\mathrm{k}\left(\frac{\left[\mathrm{SO}_{2}\right]}{2}\right)^{2}\left(\frac{\left[\mathrm{O}_{2}\right]}{2}\right)=\frac{\mathrm{r}_{1}}{8}$

$\frac{r_{1}}{r_{2}}=8: 1$