Question

Equilibrium constant for an equilibrium reaction is 100. Its forward reaction rate constant $K_f={10}^5$. Its backward reaction rate constant $K_b$ is;

• A. ${10}^2$
• B. $10$
• C. ${10}^4$
• D. ${10}^3$

Answer 1

The correct option is D ${10}^3$

The relationship between the equilibrium constant $K_c$, the rate constant $k_f$ for the forward reaction and the rate constant $k_b$ for the backward reaction is as given below.

$K_c=\frac{k_f}{k_b}$

Substitute values in the above expression.

$100=\frac{{10}^5}{k_b}$

Thus, $k_b={10}^3$.