Home › Acids › Pure Liquid Sulphurous Acid

Pure Liquid Sulphurous Acid

This can only be obtained by passing the pure dry gas through a glass tube surrounded by a powerful freezing mixture. The specific gravity of the pure liquid gas is 1.45; its ceiver; these will disappear in the course of the distillation, but subsequently renewed, pale yellow acid thus obtained may be renshowing that the process is completed. The dered colorless, if desired, by heating it gently in a retort. nitric acid of commerce frequently contains 3874. Το Purify Nitric Acid. The boiling point is 14º Fahr., and causes intense chlorine, muriatic and sulphuric acids, and cold by its evaporation.

3870. Hydrosulphuric Acid, also fied by the addition of a little nitrate of silsometimes iodine, from which it may be puri- Called Sulphuretted Hydrogen. When ver, as long as it produces any cloudiness, and, sulphur acts upon paraffine at a temperature a after repose, decanting the clear acid, and little above the melting point of sulphur, hyrectifying it at a heat under 2120 Fahr. A drosulphuric acid gas is evolved in large perfectly colorless product may be obtained, quantities, and this method may be advan- by introducing a small portion of pure black oxide of manganese into the retort. Nitric boratory. A flask, holding about a pound of acid may also be purified by rectification at a the material, is fitted with a tube bent at gentle heat, rejecting the first liquid that right angles, about½ inch bore and 12 to 18 comes over, receiving the middle portion as inches long, containing cotton wool, and to genuine acid, and leaving a residuum in the this is attached the small tube for precipitaretort. Another method is to agitate it with tion. The production of gas may be stopped by removing the heat. Heavy paraffine oil, stearic acid, or suet, may be used as a substitute for paraffine. a little red-lead before rectification.