Question

how can a concentrated solution of hydrogen peroxide be obtained​

Answer 1

Answer:

H2O2 solution cannot be concentrated by heating beyond 30% solution as there is always possibility of explosions. The solution is concentrated at 35−40∘ Cunder reduced pressure of about 15 mm. Repeated distillation gives 90% H2O2. Further concentration is achieved by cooling with the help of solid CO2 and ether bath till crystallisation sets in. Crystals are separated, melted and refrozen to get 99%  pure H2O2.