EAMCET Engineering 2006 Solved Paper

A 30% solution of hydrogen peroxide can be obtained by the electrolysis of 50% sulphuric acid followed by vacuum distillation. The first product of electrolysis is perdisulphuric acid (H2S2O8) which reacts with water during distillation to form H2O2.
2H2SO4‌→2H++2HSO4−
2HSO4−‌→H2S2O8+2e−‌(At anode) ‌
H2S2O8+2H2O‌→2H2SO4+H2O2
' X ' is H2SO4 and ' Y ' is H2S2O8. So ' X ' and ' Y ' contains zero and one peroxy bond respectively.