Question

the equivalent weight of the salt KHC2O4. H2C2O4. 4H2O used as reducing agent is M/ ?

Answer 1

equivalent weight for a reducing agent= molecular mass/ electron lost

In the redox reaction it can loose up to 4 electrons
and the molecular weight of KHC2O4. H2C2O4. 4H2O = 290g
so 
equ weight = 290/4 = 72.5 g

Answer 2

Answer:  The equivalent weight of the salt is 72.5 g

Explanation: Gram equivalent weight is the weight in grams of the compound which combines with one gram of hydrogen or eight grams of oxygen.

Gram equivalent weight is equal to ratio of gram molecular weight to the number of electrons involved in redox reaction.

Valency factor (n) for a reducing agent is the number of electrons lost.

Thus ${\text {gram equivalent weight}}=\frac{\text {Molecular weight}}{\text {number of electrons lost}}$

The molecular mass of $KHC_2O_4.H_2C_2O_4. 4H_2O$ = 290 g/mole

 $KHC_2O_4.H_2C_2O_4. 4H_2O\rightarrow 4e^-+CO_2+....$

n = total positive or total negative ions in solution = 4

Thus ${\text {gram equivalent weight}}=\frac{290}{4}=72.5g$