Define the order of chemical reaction .
Find the overall order of the following reactions :
(a) `CHCl_(3(g)) +Cl_(2(g))rarr C Cl_(4(g))+HCl_((g)),"Rate"= k[CHCl_(3)][Cl_(2)]`
(b) `2NO_((g))+O_(2(g)) rarr 2NO_(2(g)),"Rate" = k[NO]^(2)[O_(2)]`

Explanation

Order of a reaction : The order of a chemical reaction with respect to each reactant is defined as the exponent to which the concentration term of that reactant, in the rate law, is raised.
(a) Rate `=k[CHCl_(3)][Cl_(2)]` overall order is 2nd order reaction
(b) Rate `=k[NO]^(2)[O_(2)]` overall order is 3rd order reaction