why in equivalent weight of an element there need the concept of part of it by weight ?

Question

what does part of it by weight actually maen in equivalent weight of element? give answer in detail.

Answer 1

Take this equation for example:

2Fe+2 + Sn+4 = 2Fe+3 + Sn+2

Since the Sn gains or loses (for the reverse) 2 electrons where iron only does one, the equivalent weight will be molwt/2 since it takes half as much as compared to the iron. This is way for redox reactions, you must have the equation/reaction.

Answer 2

If you mean the difference between "atomic number" and the "mass number" one is the measure of Protons or positive force (Atomic number) and the other is a combination of the Number of protons and the number of neutrons equalling it's actual mass (number) or weight.