Question

$K_C$ for the synthesis of $HI$ is $5$. $K_C$ for the dissociation of $HI$ is:

• A. $50$
• B. $5$
• C. $0.2$
• D. $0.02$

Answer 1

The correct option is C $0.2$

When the reaction for the synthesis of HI is reversed, the reaction for the dissociation of HI is obtained. Hence the equilibrium constant for the dissociation of HI is the reciprocal of the equilibrium constant for the synthesis of HI. The equilibrium constant for the synthesis of HI is 5.

Hence, the equilibrium constant for the dissociation of HI is $\frac{1}{5}=0.2$.

Hence, the correct option is $\text{C}$