What are the oxidation numbers of : (a) S in `H_(2)SO_(4)`, (b) Mn in `MnO_(4)^(-)` (c) N in `NH_(4)^(+)` and (d) Al in `A1O_(2)^(-)` (e) Mn in `MnO_(4)^(-2)`

Explanation

(a) `"2(Oxidation number of H)" +" (Oxidation number of S)" + 4(-2) = 0`
`"Oxidation number of S "= -2 + 8 = +6 `
(b) `"(Oxidation number of Mn) "+ 4 (-2) = -1`
`"Oxidation number of Mn" = -1 + 8 = +7`
(c) `"(Oxidation number of N) "+4 (+1)= +1`
`"Oxidation number of N"= +1 -4=-3`
(d) `"(Oxidation number of Al) "+2 (-2)=-1`
`"Oxidation number of Al"=-1 + 4 = +3.`
(e) `"(Oxidation number of Mn) "+4 "(oxidation number of oxygen) "= -2`
`"Oxidation number of Mn"=-2 + 8 = +6`