A20.0 mL solution containing 0.2 g impure H2O2 reacts completely with 0.316 g of KMnO4 in acid solution. The purity of H2O2 (in%) is (Nearest integer) (mol.wt.ofH2O2=34mole.wt.of.KMnO4=158)
Step 1:
The redox change are:
Mn7++5e−→Mn2+
O−2→O02+2e[Eo2=M2]
∵Meq.of H2O2=Meq.of KMnO4
Step 2:
w×10000342=0.3161585×1000
∴ WH2O2=0.17 g
Step 3:
∴ % purity of sample H2O2=0170.2×100=85%