Q43 / 150 · JEE Main 2006 · Chemistry
The equilibrium constant for the reaction
$$
\mathrm{SO}_3(\mathrm{~g}) \rightleftharpoons \mathrm{SO}_2(\mathrm{~g})+\frac{1}{2} \mathrm{O}_2(\mathrm{~g})
$$
is $\mathrm{K}_{\mathrm{c}}=4.9 \times 10^{-2}$. The value of $\mathrm{K}_{\mathrm{c}}$ for the reaction
$$
2 \mathrm{SO}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \rightleftharpoons 2 \mathrm{SO}_3(\mathrm{~g})
$$
will be
- Correct answerA416
- B$2.40 \times 10^{-3}$
- C$9.8 \times 10^{-2}$
- D$4.9 \times 10^{-2}$
Solution
$\begin{aligned} \mathrm{K}_{\mathrm{c}}^{\prime} & =\left(\frac{1}{4.9 \times 10^{-2}}\right)^2 \\ & =\frac{10^4}{4.9 \times 4.9}=\frac{100 \times 100}{24.01} \\ & =4.1649 \times 100 \\ & =416.49\end{aligned}$
Hence, the correct answer is option: 'A'.