22- Tungstic acid-2-phosphates

Liu, Y. and Wang, Q. 2006. Catalytic action of phospho-tungstic acid in the synthesis of melamine salts of pentaerythritol phosphate and their synergistic effects in flame retarded polypropylene. Polym. Deg. Stab. 91 2513-2519. 

Fusion with sodium carbonate, sodium peroxide, or sodium hydroxide likewise produces soluble sodium tungstate, molybdate, vanadate, etc. The caustic fusion method is adaptable to ores containing phosphates, fluorides, or titanium. The melt is extracted with water and on acidification tungstic acid is precipitated. Fusion methods are commonly used in large scale operations. 

Produced by careful decomposition of a 12-tungstic acid-1-phosphate with KgCOa. 

All txmgstic acid arsenates resemble closely the tungstic acid phosphates in their manner of preparation and their behavior. They are only a little less stable. 

By analogy with the 18-tungstic acid-2-phosphates, compounds of this class should be classified as salts of an 18-molybdic-2-phosphoric acid H6[(P04)s (M03O9) e aq.]. 

The main types of non-ionic tensides are adducts of higher alcohols, alkylphenols and aliphatic acids with ethylene oxide. They are determined mostly by photometry, e.g. by using tungstic-phosphate acid and hydro-quinone. Non-ionic tensides are precipitated in the presence of calcium chloride with 2% tungstic-phosphate acid. After centrifuging, the dried precipitate is dissolved in concentrated HjSO and the red-brown colour caused by addition of hydroquinone is measured at 500 nm [14, 15, 21]. 

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