Question

What do you understand by the 'order of a reaction'? Identify the reaction order from each of the following units of reaction rate constant:

(i) $L^{-1}mol{s}^{-1}$

(ii) $Lmo{l}^{-1}{s}^{-1}$

Answer 1

The order of reaction with respect to a given substance (such as reactant, catalyst or product) is defined as the index, or exponent, to which its concentration term in the rate equation is raised.The sum of the powers of the concentrations of the reactants of a chemical reaction in the rate law expression is called the order of the reaction.

$Rate=k\left[A{]}^x\right[B{]}^y$

$\Rightarrow Order=x+y$

The reaction order from each of the following units of reaction rate constant:

$\left(i\right)L^{-1}mol{s}^{-1}:Zeroorder$

$\left(ii\right)Lmo{l}^{-1}{s}^{-1}:Secondorder$