Question

M is molecular weight of KMnO4. The equivalent weight of KMnO4 when it is converted into K2MnO4 is
(a) M (b) M/3 (c) M/5 (d) M/7

Answer 1

Equivalent mass= Molecular mass/No of electrons gained or lost

Thus

equivalent mass= M/1

Answer: A) M

Answer 2

Answer: (a) M

Explanation:

$MnO_4^-+e^\rightarrow MnO_4^{2-}$

Equivalent weight is calculated by dividing the molecular weight by n factor.  

${\text{Equivalent weight}}=\frac{\text{Molecular weight}}{n}$

where n = number of electrons gained or lost

${\text{Equivalent weight}}=\frac{\text{Molecular weight}}{\text {number of electrons gained or lost}}$

$MnO_4^-+e^-\rightarrow MnO_4^{2-}$

${\text{Equivalent weight}}=\frac{M}{1}=M$

Thus equivalent weight of $KMnO_4$ when it is converted into $K_2MnO_4$ is M.