0.2g sample of H2O2 required 10 ml of N KMnO4 in a tritation in the prisence of H2SO4 . Find the purity of H2O2 .

ans = 85%

10 ml of 1N KMnO₄ solution is used to titrate 0.2gm of H₂O₂

Mole of H₂O₂ = 0.2/34= 0.0588 moles

if this solution is made upto 1 ltr to titrate, we have molarity = 0.0588 M

Since H₂O₂ release 2 H⁺ ions, Its normality = 2 x 0.0588 = 0.01174 N

Using equation

N1 V1 = N2 V2

10 * 1 = 0.01174 * V2

V2 = 854ml

Hence effective 854 ml is used in 1000 ml depending on purity

hence Purity of H₂O₂ is 85.4%