Question

The unit of second order reaction rate constant is;

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

Answer 1

Answer: (C)

According to second order reaction
$2A \to $ product
rate of reaction $\frac{d [A]}{dt} \propto [A]^{2}$ or $\frac{dA}{dt}=K[A]^{2}$
$k =$ reaction rate constant
then unit of second order reaction rate constant
$K=-\frac{d[A]}{dt}\times \frac{1}{[A]^{2}}$
$=\frac{1}{s.mol\,L^{-1}}$ or $L\,mol^{-1}\, s^{-1}$