Potassium dihydrogen arsenate

Hexafluoroarsenic acid [17068-85-8] can be prepared by the reaction of arsenic acid with hydrofluoric acid or calcium fluorosulfate (29) and with alkaH or alkaline-earth metal fluorides or fluorosulfonates (18). The hexafluoroarsenates can be prepared directly from arsenates and hydrofluoric acid, or by neutrali2ation of HAsF. The reaction of 48% HF with potassium dihydrogen arsenate(V), KH2ASO4, gives potassium hydroxypentafluoroarsenate(V)... 

Aluminium Pyroarsenate, Al4(As207)3, is obtained7 by fusing at as low a temperature as possible a mixture of alumina and 15 to 16 times its weight of sodium or potassium dihydrogen arsenate colourless transparent crystals are formed on cooling. These dissolve only very sparingly in hot water, but are readily soluble in dilute acids. 

Firm transparent jellies are produced 11 when solutions of potassium dihydrogen arsenate and cadmium sulphate, of suitable concentrations, are mixed. They are unstable and crystallise into 2Cd,(AsO,)<>. 4CdHAs04.9Ha0. 

Chromium Pyroarsenate, Cr4(As207)3, is produced when a small quantity of chromium sesquioxide is fused at a low temperature with sodium or potassium dihydrogen arsenate.12 It yields green transparent... 

Colloidal manganese arsenate may be obtained in an analogous way to that described for cadmium and cobalt arsenates.7 If concentrated solutions of manganous chloride and potassium dihydrogen arsenate are mixed at the ordinary temperature, a solid jelly is formed, which remains stable for weeks but finally, rose-coloured crystals separate and the jelly partly liquefies.8 The essential constituent of the jelly appears to be the monohydrogen arsenate, MnHAs04, and the crystals are the monohydrate, MnHAs04.Ha0. 

Potassium arsenates.—Potassium arsenate, K3As04 dipotassium hydrogen arsenate, K2HAs04and potassium dihydrogen arsenate, KH2As04, have been prepared. Their heats of formation are respectively 396-2 Cal., 339-8 Cal., and 234-0 Cal.5 The last mentioned has a density of 2-851 at ordinary temperatures,6 and of 2-8675 at 9-2° C.7 Potassium meta-arsenate, KAs03, has a specific heat of 0-1568 between 17° and 99° C.8... 

POTASSIUM ARSENATE POTASSIUM ARSENATE, MONOBASIC POTASSIUM DIHYDROGEN ARSENATE POTASSIUM HYDROGEN ARSENATE... 

POTASSIUM DICHROMATE(VI) see PKX250 POTASSIUM DICHROMATE, ZINC CHROMATE, and ZINC HYDROXIDE (1 3 1) see ZFJ122 POTASSIUM DICYANOCUPRATE(l-) see PLC175 POTASSIUM DIHYDROGEN ARSENATE see ARD250 POTASSIUM DIOXIDE see PLE260 POTASSIUM DISULPHATOCHROMATE(III) see PLB500... 

Potassium dihydrogen arsenate see arsenic acid, roonopotassium salt Potassium dihydrogen phosphate... 

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