A temperature of - 55° C. is obtained by mixing Jo parts of the hexahydrate with 7 parts of snow.
In accordance with his theory of the constitution of salts Werner formulates the hexahydrate as CrC12 (OH2)4 C1.2H20.
It effloresces gradually on exposure to air and passes into the hexahydrate.
It loses four molecules of water of crystallization when heated to 100° C. and becomes anhydrous at about 300° C. The hexahydrate is dimorphous, a tetragonal form being obtained by crystallization of a solution of the heptahydrate between 20° and 30° C., and a monoclinic form between 50° and 70° C. Nickel sulphate combines with many metallic sulphates to form double salts, and also forms addition compounds with ammonia aniline and hydroxylamine.
Driclor contains the active ingredient: 20% w/w aluminum chloride hexahydrate PH.