For the reaction $4{\mathrm{NH}}_3+5{\mathrm{O}}_2\to 4\mathrm{NO}+6{\mathrm{H}}_2\mathrm{O}$ the rate of reaction with respect to ${\mathrm{NH}}_3$ is $2\times {10}^{-3}{\mathrm{Ms}}^{-1}$. Then the rate of the reaction with respect to oxygen is $-{\mathrm{Ms}}^{-1}$

rate of reaction with respect every reactant will be the same, where as rate of disappearance will be different

$4{\mathrm{NH}}_3+5{\mathrm{O}}_2\to 4\mathrm{NO}+6{\mathrm{H}}_2\mathrm{O}$

$$\begin{gathered} -\frac{1}{4}\frac{\mathrm{d}\left[{\mathrm{NH}}_3\right]}{\mathrm{dt}}=-\frac{1}{5}\frac{\mathrm{d}\left[{\mathrm{O}}_2\right]}{\mathrm{dt}} \\ \frac{\mathrm{d}\left[{\mathrm{O}}_2\right]}{\mathrm{dt}}=\frac{5}{4}\times 2\times {10}^{-3} \mathrm{M}/\mathrm{s}=2.5\times {10}^{-3} \mathrm{M}/\mathrm{s} \end{gathered}$$