Question

The unit of rate constant for a second order reaction is:

• A. ${\text{mol L}}^{-1}{\text{s}}^{-1}$
• B. ${\text{L mol}}^{-1}{\text{s}}^{-1}$
• C. ${\text{mol}}^{-2}{\text{L}}^2{\text{s}}^{-1}$
• D. $s^{-1}$

Answer 1

The correct option is B ${\text{L mol}}^{-1}{\text{s}}^{-1}$

$\text{Rate}=k[A{]}^2$
${\text{Mol L}}^{-1}{\text{s}}^{-1}=k[{\text{Mol L}}^{-1}{]}^2$
$k=\frac{{\text{Mol L}}^{-1}{\text{s}}^{-1}}{[{\text{Mol L}}^{-1}{]}^2}$
$k={\text{L mol}}^{-1}{\text{s}}^{-1}$