Answer: (4)
Equivalent weight can be calculated by using the formula
Equivalent weight = Molar mass/number of electrons lost or gained (n)
The molecular mass of KMno4 = 158.04g
In acidic medium: MnO4- + 8H +5e– –> Mn2 + 4H2O
Here n = 5
Eq wt = 158.04/5
Eq wt = 31.61g/equivqlent
In basic medium: MnO4−+ e− → MnO42−
Here n = 1
Eq wt = 158.04/1
Eq wt = 158.04g/Equivalent
In neutral medium: Mno4– + 4H+ + 3e− –> MnO2+ 2H2O
Here n = 3
Eq wt = 158.04/3
Eq wt = 52.68g/Equivalent
Ratio of equivalent mass = 3:15:5