Uranyl metaphosphate

Uranyl hydroxides, 25 430 Uranyl metaphosphates, 25 433 Uranyl nitrate, 25 428 Uranyl perchlorate crystals, 25 429 Uranyl sulfate system, 25 429 Urban air quality, 17 814—815 Urea(s), 8 206-207... 

Uranyl Phosphates.—Well-defined ortho- and pyro-phosphates exist, but little is known of uranyl metaphosphate. Several complex uranyl phosphates have been described. 

A few uranyl metaphosphates have been reported. U02(P03)2 is formed in 85% H3PO4 at 300-350 °C or by thermal decomposition of U02(H2P04)2 at 800-850 °C. In addition, there are uranyl phosphites, U02HP03-xH20, x = 0,3, and hypophosphites U02(H2P02)2 vH20. A new phosphite with a three-dimensional structure was recently prepared using hydrothermal methods. ... 

Uranium Monophosphide, UP. —Uranyl hypophospbite on strongly heating leaves a residue consisting of a mixture of uranous pyrophosphate, uranous metaphosphate, and uranium monophospMde, hydrogen alone escaping. 

Uranyl pyrophosphate, (U03)2P207, is formed as a precipitate when a solution of sodium metaphosphate is poured into a hot solution of uranyl nitrate. The tetrahydrate, (U02)2P20,.4H20, is precipitated in yellow microcrystals by double decomposition of sodium pyrophosjihate and uranyl nitrate. The hydrate loses water and yields the anhydrous salt at 120° C. Uranyl pyrojohosphate is insoluble in water, alcohol, or ether but it dissolves in excess of sodium pyrophosphate solution (see below), and also in dilute nitric acid. 

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