Question

The unit of rate constant for reactions of second order is:

• A. $L{mol}^{-1}{s}^{-1}$
• B. $L^{-1}mol{s}^{-1}$
• C. $Lmol{s}^{-1}$
• D. $s^{-1}$

Answer 1

The correct option is A $L{mol}^{-1}{s}^{-1}$

The unit of rate constant for reactions of second order is $L{mol}^{-1}{s}^{-1}$.

For second order reaction, $\text{rate}=k[A{]}^2$

$\text{mol/L - s}=k\times [\text{mol/L}{]}^2$

$k=[\text{mol/L}{]}^{-1}{s}^{-1}$

$k=L{\text{mol}}^{-1}{s}^{-1}$

Hence, option A is correct.