ISSN:
1572-8927
Keywords:
Ionization of boric acid
;
molal volume
;
effect of pressure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The apparent, φ v , and partial, $$\bar V_2 $$ molal volumes of dilute (0.02 to 0.7m) aqueous boric acid, B(OH)3, and sodium borate, NaB(OH)4, solutions have been determined from 0 to 50° C from precision density measurements. The φ v of boric acid is a linear function of the first power of concentration. For sodium borate, the Debye-Hückel theoretical limiting law slope for the φ v as a function of the square root of molar concentration is approached at all temperatures studied. The positive deviations at higher concentrations increase with decreasing temperature. The infinite-dilution volume properties of both B(OH)3 and NaB(OH)4 indicate that these solutes behave like “structure breakers” between 0 and 50°C (that is ∂2φ v ° /∂T2 is negative). The volume change for the ionization of boric acid in water $$\Delta \bar V^\circ $$ , is calculated from the volume data at various temperatures. This volume change has been used to estimate the effect of pressure on the ionization of boric acid solutions from 0 to 50°C and 0 to 1000 bars. The calculated effect of pressure on the ionization is in good agreement with direct measurements.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00651533
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