Tetrasodium pyrophosphate decahydrate

Weigh out 2.23 g (5 mmol) of tetrasodium pyrophosphate decahydrate and dissolve it in 50 mL of distilled water in a 100 mL conical flask (it may require a little heating to allow it to fully dissolve). 

Weigh out 2.68 g (6 mmol) of tetrasodium pyrophosphate decahydrate, follow steps 1-3 of Protocol 9, but allow the effluent from the column to drop into an empty 250-mL conical flask cooled in an ice bath. 

TSPP is readily crystallised from water as the decahydrate between —0.4° and 79°C, and as the anhydrous salt above 79°C. The solubiUty of tetrasodium pyrophosphate is illustrated in Figure 8. The pH of a 1% solution is 10.2. TSPP is quite stable in alkaline medium but hydrolyses rapidly to orthophosphate under acid conditions. 

Fused tetrasodium pyrophosphate is a white crystalline mass the decahydrate forms monoclinic ctSTStsds, which were measured by C.F. Rammelsberg,W. Haidinger, A. Handl, A. Scacchi, and H. Dufet.3 The axial ratios are o c=l 2873 1 1 8951, and 16. The specific gravity of anhydrous tetrasodium pyrophosphate is... 

Tetrasodium pyrophosphate CAS 7722-88-5 13472-36-1 (decahydrate) EINECS/ELINCS 231-767-1 INS450(iii)... 

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