For the non-stoichiometric reaction $2\mathrm{A}+\mathrm{B}\to \mathrm{C}+\mathrm{D}$, the following kinetic data were obtained in three separate experiments, all at 298 K. 

Initial concentration of A	Initial concentration of B	Initial rate of formation of  C in $\mathrm{mol} {\mathrm{L}}^{-1}{\mathrm{s}}^{-1}$
0.1 M	0.1 M	$1.2\times {10}^{-3}$
0.1 M	0.2M	$1.2\times {10}^{-3}$
0.2M	0.1 M	$2.4\times {10}^{-3}$

The rate law for the formation of C is 

On changing the concentration of B to twice without changing the concentration of A, there is no change in the rate of reaction. Hence, the order of the reaction with respect to B is zero. On changing the concentration of A to twice without changing the concentration of B, the rate of reaction becomes twice. Hence, the order of the reaction with respect to A is one.