Strontium Chromate, SrCrO₄

Strontium Chromate, SrCrO₄, may be obtained in rhombohedric scales by fusion of sodium and potassium chromates with strontium chloride. It is also prepared by precipitation as a yellow crystalline powder of density 3.353. Short, thick hexagonal prisms separate from very dilute solutions, and long, fine needles from concentrated. The precipitation is prevented by acetic acid. One part of strontium chromate is soluble in 831.8 parts of water at 15° C. It is easily soluble in all acids and also in molten sodium nitrate. Fresenius determined its solubility in dilute solutions of ammonia salts and in dilute alcohol.

A solid solution of strontium chromate in barium chromate is obtained by precipitating barium chromate in a solution containing strontium chromate and acetic acid. There is an approximately constant relation between the concentration of strontium in the solution and the amount retained by the precipitate.

The double chromates, SrK₂(CrO₄)₂ and Sr(NH₄)₂ (CrO₄)₂, are formed by acting upon a solution of a strontium salt with excess of a concentrated chromate solution. Compounds with mercuric chloride and hydrochloric acid, (SrCrO₄.3HgCl₂)₂.HCl and SrCrO₄. 2HgCl₂.HCl,a have also been prepared.