Express the rate of reaction in terms of the rate of change of each reactant and each product in the following equations.
(a) $3 \mathrm{ClO}^{-}(\mathrm{aq}) \longrightarrow \mathrm{ClO}_{3}^{-}(\mathrm{aq})+2 \mathrm{Cl}^{-}(\mathrm{aq})$
(b) $2 \mathrm{SO}_{2}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g}) \longrightarrow 2 \mathrm{SO}_{3}(\mathrm{~g})$
(c) $\mathrm{C}_{2} \mathrm{H}_{4}(\mathrm{~g})+\mathrm{Br}_{2}(\mathrm{~g}) \longrightarrow \mathrm{C}_{2} \mathrm{H}_{4} \mathrm{Br}_{2}(\mathrm{~g})$
(d) $\left(\mathrm{C}_{2} \mathrm{H}_{5}\right)_{2}(\mathrm{NH})_{2}+\mathrm{I}_{2} \longrightarrow\left(\mathrm{C}_{2} \mathrm{H}_{5}\right)_{2} \mathrm{~N}_{2}+2 \mathrm{HI}$
(liquid phase)