WBJEE 2014 Chemistry Solved Paper

10 volume H2O2 means
1 mL H2O2 solution produces 10 mL O2 at STP
2H2O2 → 2H2O + O2
22400 mL O2 at STP is produced from 68 g. H2O2
∴ 10 mL O2 is produced from

68×10

22400

g = 0.03036 g H2O2
∴ 1 mL H2O2 solution contains 0.03 g H2O2 (approx.)
∴ 100 mL H2O2 solution contains 0.03 × 100
= 3 g H2O2 (approx.)