Hydrogen peroxide boiling point

Pure hydrogen peroxide is a colourless, viscous liquid, m.p. 272.5 K, density l,4gcm . On heating at atmospheric pressure it decomposes before the boiling point is reached and a sudden increase of temperature may produce explosive decomposition, since the decomposition reaction is strongly exothermic ... 

Rea.ctlons, When free (R-R, R -tartaric acid (4) is heated above its melting point, amorphous anhydrides are formed which, on boiling with water, regenerate the acid. Further heating causes simultaneous formation of pymvic acid, CH COCOOH pyrotartaric acid, HOOCCH2CH(CH2)COOH and, finally, a black, charred residue. In the presence of a ferrous salt and hydrogen peroxide, dihydroxymaleic acid [526-84-1] (7) is formed. Nitrating the acid yields a dinitro ester which, on hydrolysis, is converted to dihydroxytartaric acid [617 8-1] (8), which upon further oxidation yields tartronic acid [80-69-3] (9). 

Hydrogen peroxide, H202, is a syrupy liquid with a vapor pressure lower than that of water and a boiling point of 152<>C. Account for the differences between these properties and those of water. 

Preparation of Benzoyl Peroxide.1—Hydrogen peroxide (50 c.c. of about 10 per cent aqueous solution) kept well cooled in ice and continually shaken (preferably in a glass-stoppered bottle) is treated alternately with 4 A-sodium hydroxide solution and benzoyl chloride, added each a few drops at a time the solution is maintained faintly alkaline throughout. After about 30 c.c. of alkali and 15 g. of benzoyl chloride have been used up, the hydrogen peroxide has been decomposed and the benzoyl peroxide has separated in crystalline flocks, while the odour of the chloride has almost completely disappeared. The peroxide is filtered with suction, washed with water, and dried. Yield 10-12 g. Crystallised from a little alcohol, with which it should be boiled for a short time only, the substance forms beautiful colourless prisms. Melting point 106°-108° decomp. Heat a small quantity rapidly in a dry test tube over a naked flame. An especially pure product is obtained when a 1 von Pechmann and Vanino, Ber., 1894, 27, 1510. 

It is usual to carry out the reaction in water or ethanol, or in mixtures of the two, at temperatures ranging from 60° to the boiling point, for from 2 to 12 hours. Butanol has also been used as a solvent [82, 136] and, exceptionally xylene [137] and dimethylformamide [138], or even no solvent at all [136] The alkyl mercaptan which is evolved in this reaction can be absorbed in a solution of sodium hydroxide and hydrogen peroxide [135] or in a charcoalicupric chloride trap [139]. The guanidines are often conveniently isolated via their relatively insoluble bicarbonates [118, 139]. 

For this, we need the molar volume GB of hydrogen peroxide at normal boiling point, which can be evaluated using the following correlation (see eq. (1.26) in Appendix I) ... 

Atmospheric Boiling Points of Hydrogen Peroxide Solutions... 

Liquid water is clear, colourless, odourless, and transparent. Hydrogen peroxide (an antiseptic liquid that many people use to clean wounds) has the same properties. It differs from water, however, in other properties, such as boiling point, density, and reactivity with acids. 

Figure 1.15 Boiling point range of hydrogen peroxide-water mixtures.

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