The volume of oxygen liberated from 15 mL of 20 volume H₂O₂ is

20 volume 2 2 H O means one litre (1000 mL) of hydrogen peroxide on decomposition gives twenty litres (20 L = 20000 mL) of oxygen at standard temperature conditions (STP). Given, Volume of hydrogen peroxide = x mL Let the volume of oxygen = 15 mL Volume of hydrogen peroxide Volume of oxygen 1000 mL 20000 mL 15 mL x mL Solving for x, we get 20,000 15 3,00,000 x 300 mL 1000 1000 x Therefore, the volume of oxygen liberated from 15 mL of “20 volume H₂O₂” is 300 mL.