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Hydrogen Peroxide. Hydrogen peroxide. Methods of preparation. 2. From Barium peroxide. Barium sulphate is filtered off leaving behind H 2 O 2. H 2 SO 4. 3. By electrolysis of 50% H 2 SO 4. At cathode. At Anode. H 2 O 2 distills first leaving behind the H 2 SO 4 which is recycled.
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Hydrogen peroxide Methods of preparation 2. From Barium peroxide Barium sulphate is filtered off leaving behind H2O2.
H2SO4 3. By electrolysis of 50% H2SO4 At cathode At Anode H2O2 distills first leaving behind the H2SO4 which is recycled.
4. By auto oxidation of 2-ethylanthraquinol The H2O2 obtained by this method is further concentrated by distillation under reduced pressure.
PhysicalProperties • In the pure state H2O2 is an almost colourless • (very pale blue) liquid. • H2O2 is miscible with water in all proportions and forms a hydrate H2O2.H2O • A 30% solution of H2O2 is marketed as ‘100 volume’ hydrogen peroxide.
Oxidising properties Chemical Properties
Acidic properties It reacts with alkalies and decomposes carbonates.
Uses of hydrogen peroxide • For bleaching silk, wool, hair and leather • As rocket fuel • Dilute solution is sold in name ‘perhydrol’ • It is used in the synthesis of hydroquinone, tartaric acid and certain food products and pharmaceuticals (cephalosporin) etc.
Storage H2O2 decomposes slowly on exposure to light. H2O2 is stored in the bottles lined with wax because the rough glass surface causes the decomposition of hydrogen peroxide.
Volume strength of hydrogen peroxide Calculate the percentage strength of a 10 volume H2O2 solution. 10 volume hydrogen peroxide means that 1 ml of such a solution of hydrogen peroxide on heating will produce 10 ml of oxygen at N.T.P. 2(2 + 32) gm 22.4L at N.T.P. = 68 gm or 22400 cm3 at N.T.P.
Solution But 10 ml of O2 at N.T.P. are produced from 1 ml of 10 volume H2O2 solution. = 0.03035 gm
Illustrative example Calculate the normality of 30 volume of H2O solution: Solution: 2(2 + 32) gm 22.4 L= 68 gm 22.4 L of O2 is produced from = 68 gm of H2O2 = 91.07 gm/mL
Solution 68 parts by weight 32 parts by weight 32 parts by weight of oxygen is obtained from = 68 parts by weight of H2O2 parts by weight of oxygen is obtained from =