Question

2.8 of iron displaces 3.2 g of copper from copper sulphate solution.if equivalent mass of iron is 28,find equivalent mass of copper

Answer 1

Dear Student


Mass of Fe = 2.8 g

Mass of Cu = 3.2 g

Eq. Mass of Fe = 28

Eq. Mass of Cu = ???


The reaction involved is:

CuSO₄ + Fe ---> FeSO₄ + Cu

So, a single displacement reactio has taken place between Fe and Cu, where

Fe²⁺ ions have displaced Cu²⁺ from the CuSO₄ solution

We know,

Equivalent Weight = $\frac{MolarMass}{Valence}$


Molar Mass of Cu = 63.5 g/mol

​Valency of Cu = 2

[ because, SO₄ holds -2 charge, thus, Cu will have +2 charge to make it balanced]


So, Equivalent Weight of Cu = $\frac{63.5}{2}$ = 31.75 $\approx$ 32


Regards