Discuss, with relevant chemical equations, various methods of preparing hydrogen peroxide. Which of these methods is useful to prepare `D_(2)O_(2)`?

Explanation

Hydrogen peroxide can be prepared by the following method.
(1) By adding ice cold dilute sulphuric acid to barium peroxide gives hydrogen peroxide.
`BaO_(2). 8H_(2)O (s) + H_(2)SO_(4)(aq) to BaSO_(4) + H_(2)O_(2) + 8H_(2)O`
`BaSO_(4)` can be removed by filtration Excess water can be removed by evaporation under reduced pressure.
(2) Electrolysis of `50% H_(2)SO_(4)` using platinum anode and lead cathode gives `H_(2)O_(2)`.
`2H_(2)SO_(4) to 2H^(+) + 2HSO_(4)^(-)`
`2HSO_(4)^(-) (aq) overset("Electrolysis")(rarr) underset("perdisulphuric acid")(H_(2)S_(2)O_(8)(aq)+2e^(-))`
Hydrolysis of perdisulphuric acid gives hydrogen peroxide.
`H_(2)S_(2)O_(8) + 2H_(2)O to 2H_(2)S_(4) + H_(2)O_(2)`
(3) Industrially it is prepared by the auto oxidation of 2- alkylanthraquinols.

`K_(2)S_(2)O_(8)` is used for the preparation of `D_(2)O_(2)`
`D_(2)O_(2)` can be prepared by dissolving `K_(2)S_(2)O_(8)` in heavy water.
`K_(2)S_(2)O_(8) + 2D_(2)SO_(4)+D_(2)O_(2)`.