Question

For the reaction $NO _{2}+ CO \rightleftharpoons NO + CO _{2}$ one mole of $NO _{2}$ and 2 moles of $C O$ were kept in a vessel. Calculate the equilibrium constant $K_{p}$ if at equilibrium $25 \%$ of initial amount $CO$ is consumed

• A. $\frac{1}{2}$
• B. $\frac{1}{3}$
• C. $1$
• D. $\frac{1}{4}$

Answer 1

Answer: (B)

In this question, we have to assume that volume of the vessel is $1\, L$.

Given, $\alpha=2 \times \frac{25}{100}=0.5$
$\Rightarrow K_{C}=\frac{[N O]\left[C O_{2}\right]}{\left[N O_{2}\right][C O]}$
$=\frac{0.5 \times 0.35}{0.5 \times 1.5}=\frac{1}{3}=K_{p}$
Because, $\Delta n_{g}=(1+1)-(1+1)=0$
$\Rightarrow K_{p}=K_{C}(R T)^{\Delta n_{\varepsilon}}=K_{C}(R T)^{0}=K_{C}$
$\Rightarrow K_{p}=\frac{1}{3}$