Rate constant of two reactions are given below. Identify their order of reaction.
$$\eqalign{ & \left( {\text{i}} \right)k = 5.3 \times {10^{ - 2}}\,L\,mo{l^{ - 1}}\,{s^{ - 1}} \cr & \left( {{\text{ii}}} \right)k = 3.8 \times {10^{ - 4}}\,{s^{ - 1}} \cr} $$

Solution :
$$\eqalign{ & {\text{For second order, rate constant}} \cr & = \frac{{mol\,{L^{ - 1}}}}{s} \times \frac{1}{{{{\left( {mol\,{L^{ - 1}}} \right)}^2}}} \cr & = mo{l^{ - 1}}\,L\,{s^{ - 1}} \cr & {\text{For first order, rate constant}} \cr & = \frac{{mol\,{L^{ - 1}}}}{s} \times \frac{1}{{mol\,{L^{ - 1}}}} = {s^{ - 1}} \cr} $$