Symbol, KBr. Atomic weight, 118.
Bromide of potassium is prepared by adding bromine to caustic potash, and heating the product, which is a mixture of bromide of potassium and bromate of potash, to redness, in order to drive off the oxygen from the latter salt. It crystallizes in anhydrous cubes, like the chloride, and iodide, of potassium; it is easily soluble in water, but more sparingly so in alcohol; it yields red fumes of bromine when acted upon by sulphuric acid.
Bromide of Silver. (See [Silver, Bromide of.])
Carbonate of Soda.
Symbol, NaO CO{2} + 10 Aq.
This salt was formerly obtained from the ashes of seaweeds, but is now more economically manufactured on a large scale from common salt. The chloride of sodium is first converted into sulphate of soda, and afterwards the sulphate into carbonate of soda.
Properties.—The perfect crystals contain ten atoms of water, which are driven off by the application of heat, leaving a white powder—the anhydrous carbonate. Common washing soda is a neutral carbonate, contaminated to a certain extent with chloride of sodium and sulphate of soda. The carbonate used for effervescing draughts is either a bicarbonate with 1 atom of water, or a sesquicarbonate, containing about 40 per cent, of real alkali; it is therefore nearly double as strong as the washing carbonate, which contains about 22 per cent, of soda. Carbonate of soda is soluble in twice its weight of water at 60°, the solution being strongly alkaline.
Carbonate of Potash. (See [Potash, Carbonate of.])
Caseine. (See [Milk.])
Charcoal, Animal.