A 1% solution of `H_(2)O_(2)` is provided to you. What steps do you take to prepare pure `H_(2)O_(2)` from it?

Explanation

The concentration of `H_(2)O_(2)` involves three stages.
Stage (1) : The dilute solution of `H_(2)O_(2)` is carefully evaporated on a water bath under reduced pressure. Then 30% `H_(2)O_(2)` solution is obtained.
Stage (2) : The 30% `H_(2)O_(2)` solution is heated in a distillation flask under reduced pressure. Then 90% `H_(2)O_(2)` is obtained.
Stage (3) : The 90% `H_(2)O_(2)` solution is subjected to crystallisation using solid `CO_(2)` and ether. Then 100% `H_(2)O_(2)` separates out.