double salt

American  

noun

Chemistry.

1. a salt that crystallizes as a single substance but ionizes as two distinct salts when dissolved, as carnallite, KMgCl 3 ⋅6H 2 O.

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double salt British  

noun

1. a solid solution of two simple salts formed by crystallizing a solution of the two salts Compare complex salt

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double salt Scientific  

1. A salt that crystallizes from an aqueous solution of a mixture of two different ions. The mineral dolomite (CaMg(CO ₃) ₂), for example, is a double salt that crystallizes from a solution containing both calcium and magnesium ions. Double salts exist only as solids.

2. Compare complex salt simple salt

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Etymology

Origin of double salt

First recorded in 1840–50

Example Sentences

See Examples For:

double salt

It said that all 27 trunk routes in the south west of the country would receive double salt treatments at 13:00 and 01:00 throughout the week.

From BBC ● Jan. 5, 2026

Alum.—This is what is termed a double salt, and is composed of sulphate of alumina and sulphate of potash.

From Museum of Antiquity A Description of Ancient Life by Haines, T. L. (Thomas Louis)

Tin may be easily estimated by electrolysis; it can be separated from its hydrochloric acid solution, or from its double salt with ammonium oxalate, as a beautiful silver gray coating on the platinum.

From Scientific American Supplement, No. 299, September 24, 1881 by Various

The electrolytic separation of cobalt is much more easily and rapidly effected when the potassium oxalate is substituted by the corresponding ammonium salt, as the latter forms a soluble double salt with the cobalt compounds.

From Scientific American Supplement, No. 299, September 24, 1881 by Various

By leaving the hot saturated solution to cool it does not cloud, but the double salt separates pretty rapidly in the form of plates.

From Scientific American Supplement, No. 324, March 18, 1882 by Various