Metaarsenates Arsenate-phosphate

Densities of the crystals and the glasses of sodium meta-arsenate-phos-phates vary linearly with composition, between those of pure sodium metaarsenate and pure sodium metaphosphate, as shown in Figure 3. Therefore, the density of crystalline or glassy sodium meta-arsenate-phosphate, dAsP is represented by equation 13 ... 

The Relations among the Modifications of Potassium Metaphosphate, Potassium Metaarsenate, and Potassium Meta-Arsenate-Phosphate... 

On the other hand there are three modifications of potassium metaarsenate, KAs03-a, -/ , and -7. Transitions between these modifications are shown in Figure 5. There are also three modifications of potassium meta-arsenate-phosphate rich in arsenic, K(As,P)03-a, -/5, and -7, which... 

Fig. 6. The transition temperatures and melting temperatures of various modifications of potassium metaphosphate, potassium metaarsenate, and potassium meta-arsenate-phosphates (61). O Melting temperatures of A and a forms. 9 Transition temperatures between A and B forms and between a and p forms. Transition temperatures between B and C forms and between p and y forms.

Condensed arsenic anions are much less stable than the condensed phosphates and, owing to rapid hydrolysis, do not exist in aqueous solution. Dehydration of KH2As04 gives three forms, stable at different temperatures, of metaarsenate one form is known to contain an infinite chain polyanion, and another contains the cyclotriarsenate ion, [As309]3 . 

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