Equivalent weight of Oxidising and Reducing Agents
Equivalent weight of a substance (oxidant or reductant) is equal to molecular weight divided by number of electrons lost or gained by one molecule of the substance in a redox reaction.
Eq. wt. of O. A. = 
=
Eq. wt. of R. A. = 
= 
Table : Equivalent weight of few oxidising/reducing agents
| Agents | O. N. | Product | O. N. | Change in O. N. per atom | Total Change in O. N. per mole | Eq. wt. |
 | + 6 |  | + 3 | 3 | 3 × 2 = 6 | Mol. wt./6 |
 | + 3 |  | + 4 | 1 | 1 × 2 = 2 | Mol. wt./2 |
 | + 2 |  | + 2.5 | 0.5 | 0.5 × 2 = 1 | Mol. wt./1 |
 | – 1 |  | – 2 | 1 | 1 × 2 = 2 | Mol. wt./2 |
| – 1 |  | 0 | 1 | 1 × 2 = 2 | Mol. wt./2 |
 (Acidic medium) | + 7 |  | + 2 | 5 | 5 × 1 = 5 | Mol. wt./5 |
(Neutral medium) | + 7 |  | + 4 | 3 | 3 × 1 = 3 | Mol. wt./3 |
(Alkaline medium) | + 7 |  | + 6 | 1 | 1 × 1 = 1 | Mol. wt./1 |