A manual of chemistry, inorganic and organic : inorganic and organic, with an introduction to the study of chemistry / by Arthur P. Luff.

  • Luff, Arthur P. (Arthur Pearson), 1855-1938.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: A manual of chemistry, inorganic and organic : inorganic and organic, with an introduction to the study of chemistry / by Arthur P. Luff. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    103/558 (page 83)
    of liyilrugeu evolved is double that of the oxygen, although if the volumes of the gases aie very accu- rately compared, it will be found that the oxygen measures slightly less than one-half the volume of the hydrogen, this slight difference being due to the greater solubility of oxygen in water, as compared with hydrogen. (b) Decomposition of water by chlorine.—If chlorine and steam be passed through a porcelain tube con- taining fragments of pumice-stone heated to bright redness, the chlorine unites with the hydrogen of the water, forming hydrochloric acid, and the oxygen is set free : 2CL + 2H2O = 4HC1 -f O. Chlorine. Water. Hydroolilorio Oxygen. acid. If the mixture of hydrochloric acid gas and oxygen be passed through a strong solution of caustic potash, the former is absorbed, potassium chloride being formed, and the oxygen is then obtained in the pure state. (vii) Oxygen may be obtained from the atmo- sphere, in which it naturally occurs mixed with nitro- gen in the proportions of 21 volumes of oxygen to 79 of nitrogen. As there is no method of absorbing the nitrogen from a limited amount of air, and so leaving tlie oxygen in the pure state, the method that must be resorted to, if it is desired to obtain pure oxygen from the air, is to roast some substance in contact with the air, which at one temperature will absorb or combine ■with the oxygen of the air, and at another temperature will give up in a pure state the oxygen so taken from the air. The two simplest processes for effecting this are («) the mercury process, and (b) the baryta process.