Question

In a chemical reaction,the rate constant for the backward reaction is $7.5\times {10}^{-4}$ and the equilibrium constant is $1.5$ the rate constant for forward reaction is:

• A. $5\times {10}^{-4}$
• B. $1.125\times {10}^{-3}$
• C. $9\times {10}^{-4}$
• D. $2\times {10}^{-3}$

Answer 1

The correct option is B $1.125\times {10}^{-3}$

Equilibrium constant for a recation: $K_c=\frac{\text{rate of forward reaction}}{\text{rate of backward reaction}}=\frac{r_f}{r_b}$

$\Rightarrow 1.5=\frac{\text{rate of forward reaction}}{7.5\times {10}^{-4}}$
$\Rightarrow \text{Rate of forward reaction}=1.5\times 7.5\times {10}^{-4}=1.125\times {10}^{-3}$.