Question

Units of rate constant for the first and zero order reactions in terms of molarity M units are respectively:

• A. $se{c}^{-1},Mse{c}^{-1}$
• B. $se{c}^{-1},M$
• C. $Mse{c}^{-1},se{c}^{-1}$
• D. None of the above

Answer 1

Answer: (A)

$se{c}^{-1},Mse{c}^{-1}$

The unit of the rate constant K is ${\left(\text{Molarity}\right)}^{1-n}tim{e}^{-1}.$

Here, n is the order of the reaction.

For first order reaction, $n=1.$

The unit of the rate constant K is ${\left(\text{Molarity}\right)}^{1-1}se{c}^{-1}=se{c}^{-1}.$

For zero order reaction, $n=0.$

The unit of the rate constant K is ${\left(\text{Molarity}\right)}^{1-0}se{c}^{-1}=\left(\text{Molarity}\right)se{c}^{-1}=\left(M\right)se{c}^{-1}.$