Thallous dichromate

Thallous Dichromate, TlaCrjOj, is precipitated as an orange-red crystalline powder when solutions of a soluble thallous salt and potassium dichromate are mixed, and is also obtained by the action of sulphuric acid on the chromate. ... 

Thallous Chromate, Tl2Gr04, is precipitated when a solution of a thallous salt is mixed with potassium chromate. It is also produced by adding thallous hydroxide or carbonate to aqueous chromic acid, or by the action of ammonia on the dichromate. Thallous chromate is a yeUow crystalline powder, very sparingly soluble in water, 100 grams of which dissolve 0-03 gram of the salt at 60° C., and 0-2 gram at 100° C. ... 

Thallous Trichromate, TlgCrgOjo, a red, crystalline, sparingly soluble salt, is obtained by the action of nitric add on the dichromate, or of concentrated sulphuric acid on the chromate. 

W. Crookes 7 obtained thallous trichromate, TlgCrgOio, by digesting the chromate with sulphuric acid and J. E. Willm, by digesting the dichromate with nitric acid. The red, crystalline powder behaves hke the monochromate towards aq. and alcoholic hydrochloric acid. 100 grms. of water at 15° dissolve 0 0355 grm. of the trichromate, and at 100°, 0 2283 grm. 

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