When boiled with water it forms the ortho-acid, and when heated to redness the metaacid.
The substance is heated with metallic sodium or potassium (in excess if sulphur be present) to redness, the residue treated with water, filtered, and ferrous sulphate, ferric chloride and hydrochloric acid added.
The purification by liquation is assisted by poling the lead when it is below redness.
Uranous chloride, UC14, was first prepared by Peligot by heating an intimate mixture of the green oxide and charcoal to redness in a current of dry chlorine; it is obtained as sublimate of black-green metallic-looking octahedra.
Ammonium uranate heated to redness yields pure U308, which serves as a raw material for uranium compounds.
