Normal0falsefalsefalseEN-USX-NONEX-NONE/* Style Definitions */table.MsoNormalTable{mso-style-name:Table Normal;mso-tstyle-rowband-size:0;mso-tstyle-colband-size:0;mso-style-noshow:yes;mso-style-priority:99;mso-style-qformat:yes;mso-style-parent:;mso-padding-alt:0in 5.4pt 0in 5.4pt;mso-para-margin-top:0in;mso-para-margin-right:0in;mso-para-margin-bottom:10.0pt;mso-para-margin-left:0in;line-height:115%;mso-pagination:widow-orphan;font-size:11.0pt;font-family:Calibri,sans-serif;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Times New Roman;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:Times New Roman;mso-bidi-theme-font:minor-bidi;}Concentration of Hydrogen Peroxide

Concentration of Hydrogen Peroxide: - Thy hydrogen peroxide obtained by the above methods is extracted with water and the aqueous solution is concentrated. It may be noted that the concentration of the solution cannot be done by simple boiling because; hydrogen peroxide decomposes by the following steps.

(i)          Evaporation on a water bath: - The dilute solution of hydrogen peroxide is transferred to an evaporating dish and warmed carefully on a water bath. In this process about 30% solution of H2O2 is obtained.

(ii)         Dehydration in vacuum desiccators: - The above solution of hydrogen peroxide is placed over concentrated sulphuric acid in vacuum desiccators. The water vapours are absorbed by concentrated sulphuric acid and, thus, about 90% concentrated solution of hydrogen peroxide is obtained.

(iii)        Distillation under reduced pressure: - The 90% solution of hydrogen peroxide is then distilled under reduced pressure. During this process, water distils over at 3030-313K and 99% pure hydrogen peroxide is lift behind.

(iv)       Removal of last traces of water: - The 99% solution of hydrogen peroxide is cooled in freezing mixture of solid carbon dioxide and ether. As a result of this, crystals of hydrogen peroxide separate out which are removed, dried and remelted. This gives completely pure hydrogen peroxide.