Give a method for the manufacture of hydrogen peroxide and explain the reactions involved therein .
(ii) Illustrate oxidising, reducing and acidic properties of hydrogen peroxide with equations.

Explanation

(i) `H_(2)O_(2)` is industrially manufactured by the auto-oxidation of 2 alkylanthraquinols
In this case 2-ethylanthraquinol `underset(H_(2)//Pd)overset(O_(2)//("air"))hArr H_(2)O_(2)+` Oxidised product
In this case 1% `H_(2)O_(2)` is formed . It is extracated with water and concetrated to `~ 30%` (by mass) by distillation under reduced pressure.
It can be further concentrated to `~ 85%` by careful distillation under low pressure. The remaining water can be frozen out to obtain pure `H_(2)O_(2)`.
(ii) `H_(2)O_(2)` acts as an oxidising as well reducing agent in both acidic and alkaline media.
Following reactions are described below.
(a) Oxiding aciton in acidic medium
`2Fe^(2+)(aq) + 2H^(-)(aq) +H_(2)O_(2)(aq) to 2Fe^(3+) (aq) + 2H_(2)O(l)`
`PbS(s)+ 4H_(2)O_(2)(aq) to PbSO_(4)(s) + 4H_(2)O(l)`
(b) Reducing action medium
`2MnO_(4)^(-) + 6H^(+) + 5H_(2)O_(2) to 2Mn^(2+) + 8H_(2)O (l)`
`HOCl + H_(2)O_(2) to H_(3)O_(2) to H_(3)O^(+) + 2OH^(-)`
(c)Oxiding acitons in basic medium
`2Fe^(2+) + H_(2)O_(2) to 2Fe^(3+) + 2OH^(-)`
`Mn^(2+) +H_(2)O_(2) to Mn^(4+) + 2OH^(-)`
(d) Reducing action in basic medium
`I_(2) + H_(2)O_(2) + 2OH^(-) to 2I^(-) + 2H_(2)O + O_(2)`
`2MnO_(4) + 3H_(2)O_(2) to 2MnO_(2) + 3O_(2)+ 2H_(2)O + 2OH^(-)`