pK Values for D,O and H,O Drs. R. G. Bates, R. A. Robinson, and A. K. Covingtonl working a t the National Bureau of Standards for IWaterials Research have determined the pK of heavy water over the 5-50°C temperature range. The following table gives the pK values for heavy water, as calculated from the NBS data, and the literature values for pK for ordinary water. Values are shown for the mold scde (pK,), thc molarity scale (pK.), and the mole fraction scale (pK,,), over the range from 10 to 50°C.
10 20 25 30 40 50
15.526 15.136 14.955 14.784 14.468 14.182
17.224 16.384 16.663 16.482 16.166 15.880
15.439 15.049 14.869 14.699 14.385 14.103
Covrswan A. K. Roe~nsolr.R. A,.
AND
14.535 14.167 13.997 13.833 13.5'35 13.262
14.535 14.169 14000 13.837 13.542 13.272
16.279 15.911 15.741 15.577 15.279 15.006
BATEB. R O ~ EG., R . I P. h y ~ Chorn.. . 70, 3820 (1966).
Volume 44, Number 1 I , November 1967
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