Activities of Alkali Metal Citrates at Freezing Point Temperatures

3 Activities of Alkali Metal Citrates at Freezing Point Temperatures 

Systematic determination of freezing points is known only in case of aqueous solutions of alkali metal acidic and neutral citrates. Apelblat and Manzuiola [149] measmed freezing-point depressions for sodium 

Few freezing-point depressions of tripotassium citrate were also reported by Fricke and Schutzdeller [150] in 1924 (Table 5.5). These values are consistent with those of Apelblat and Manzurola [149], but they are systematically lower by about 0.1 K. 

From the knowledge of dim) values, by using thermal properties of pure water, it is possible to determine the water activities a of inorganic citrates from [151] 

However, in calculations, Apelblat and Manzurola [149] assumed that all alkali metal citrates can be treated as strong electrolytes, but of dififetent types, NaH2Cit and KH2Cit ate 1 1 electrolytes, Na HCit is 1 2 electrolyte and NajCit and K3Cit ate 1 3 electrolytes. In this case, the osmotic coefficients can be written in the usual form 

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Activities of Alkali Metal Citrates at Freezing Point Temperatures Table 5.5 Freezing temperatures in the alkali metal citrate - water systems [149]... 

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