ISSN:
1572-8927
Keywords:
Acid-base indicator
;
association constant
;
sodium fluoride ion pair
;
partial molal volume
;
and compressibility change
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The effect of pressure on the dissociation constant of hydrofluoric acid was determined by using the indicator technique at 25°C at an ionic strength of 0.1m over a pressure range of 1 to 2000 atm. A value of 3.14 for pK a * at I =0 was obtained by extrapolation to zero ionic strength at 1 atm. The pressure dependence yielded a partial molar volume change of −9.6 cm3-mol−1 and a compressibility change of — 35×10−3 cm3-mol−1 −atm−1 for the dissociation. The dependence of ionic strength on the association constant K A * of NaF was studied at 25°C and 1 atm. Extrapolation to I=0 yielded a pK A * of −0.78. The pressure dependence of K A * gave a change of volume of 3.26 cm3-mol−1 and a change in compressibility of 6×10−3 cm3-mol−1-atm−1 for the formation of the ion pair.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00649700
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