Thallous 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. ... 

In hot concentrated potassium hydroxide solution thallous chromate is fairly soluble, and it separates out on cooling in crystals which are apparently isomorphous with potassium chromate. At a dull red heat the chromate melts, and at higher temperatures it loses oxygen. 

Defined as those containing only the simple MO ions, they can be obtained from solutions of M03 in aqueous alkali. The MO ions persist as such in basic solution. Although both molybdates and tungstates can be reduced in solution (see later), they lack the powerful oxidizing property so characteristic of chromates(VI). The normal tungstates and molybdates of many other metals can be prepared by meta-thetical reactions. The alkali metal, ammonium, magnesium, and thallous salts are soluble in water, whereas those of other metals are nearly all insoluble. 

Neurotoxic chemicals and motor neuropathy Chlorpyrifos, dichlorvos (DDVP), EPN, n-hexane, 2-hexanone, lead, lead chromate, lead II thiocyanate, leptophos, methamidophos, mipafox, omethoate, parathion, trichlor-fon, trichloronate, triorthocresyl phosphate Neurotoxic chemicals and sensorimotor neuropathy acrylamide, allyl chloride, arsenic and compounds, arsenic trichloride, calcium arsenate, carbon disulfide, dichloroacetylene, ethylene oxide, gallium arsenide, lead arsenate, mercuric chloride, mercuric nitrate, mercurous nitrate, mercury, nitrous oxide, phenyl arsine oxide, thallium and soluble compounds, thallous nitrate... 

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 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. 

---