Question

The equilibrium constant for the reaction $N_2\left(g\right)+O_2\left(g\right)=2NO\left(g\right)$at temperature $T$ is $4\times {10}^{-4}$. The value of $K_c$ for the reaction:

$NO\left(g\right)$ $=\frac{1}{2}{N}_2\left(g\right)+\frac{1}{2}{O}_2\left(g\right)$ at the same temperature is :

• A. $2.5\times {10}^2$
• B. $50$
• C. $4\times {10}^{-4}$
• D. $0.02$

Answer 1

Answer: (B)

$50$

The equilibrium constant for the reaction $N_2\left(g\right)+O_2\left(g\right)=2NO\left(g\right)$at temperature $T$ is $4\times {10}^{-4}$. The value of $K_c$ for the reaction:
NO(g) $=\frac{1}{2}{N}_2\left(g\right)+\frac{1}{2}{O}_2\left(g\right)$ at the same temperature is $\frac{1}{\sqrt{K_c}}=\frac{1}{\sqrt{4\times {10}^{-4}}}=50$
Note: The second reaction is obtained when the first reaction is reversed and divided by 2.