$\text{ What is the equivalent mass of }{\mathrm{O}}_2\text{ in the following reaction, }{\mathrm{H}}_2\mathrm{O}+\frac{1}{2}{\mathrm{O}}_2+2{\mathrm{e}}^{-}⟶2{\mathrm{OH}}^{-}?$

$\text{ Equivalent mass }{\mathrm{O}}_2=\frac{32}{4}=8$,equivalent mass is always calculated with respect to one mole of substance.