The individual rate constants for each of the reactions occurring during the degradation of sodium hexaphosphate, derived from trömelite, were determined at 65.5°C. and pH 5. Since pentaphosphate was produced in significant amounts it was possible to calculate the rate constants for each of the reactions occurring during its degradation also. These constants demonstrate that these phosphates degrade mainly by two routes, the first and faster producing orthophosphate with a chain shorter by one phosphate unit and the second producing trimetaphosphate with a chain shorter by three phosphate units. The rate constants for the hydrolysis of polyphosphates with DP < 5 were redetermined. The constant for the degradation of tetraphosphate presented here differs from that published previously, while the constants for tri‐ and pyrophosphate check with those obtained by other workers.

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