The dissociation quotients of formic acid in sodium chloride solutions to 200[degrees]C

Journal Article · Mon Feb 01 04:00:00 EST 1993 · Journal of Solid State Chemistry; (United States)

OSTI ID:6709085

Bell, J L.S.; Wesolowski, D J; Palmer, D A ^[1]

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1. Oak Ridge National Lab., TN (United States)

The dissociation quotients of formic acid were measured potentiometrically from 25 to 200[degrees]C in NaCl solutions at ionic strengths of 0.1, 0.3, 1.0, 3.0, and 5.0 mol-kg[sup [minus]1]. The experiments were carried out in a concentration cell with hydrogen electrodes. The resulting molal acid dissociation quotients for formic acid, as well as a set of infinite dilution literature values and a calorimetrically-determined enthalpy of reaction, were fitted by an empirical equation involving an extended Debye Hueckel term and seven adjustable parameters involving functions of temperature and ionic strength. This regressional analysis yielded the following thermodynamic quantities for 25[degrees]C: logK = [minus]3.755[plus minus]0.002, [Delta]H[degrees] = [minus]0.09[plus minus]0.15 kJ-mol[sup [minus]1], [Delta]S[degrees] = [minus]72.2[plus minus]0.5 J-K[sup [minus]1]-mol[sup [minus]1], and [Delta]C[degrees][sub p] = [minus]147[plus minus]4 J-K[sup [minus]1]-mol[sup [minus]1]. The isocoulombic form of the equilibrium constant is recommended for extrapolation to higher temperatures. 29 refs., 4 figs., 3 tabs.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6709085
• Journal Information: Journal of Solid State Chemistry; (United States), Journal Name: Journal of Solid State Chemistry; (United States) Vol. 22:2; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
AQUEOUS SOLUTIONS
CARBOXYLIC ACIDS
CHLORIDES
CHLORINE COMPOUNDS
DISPERSIONS
DISSOCIATION
ENTHALPY
ENTROPY
FORMIC ACID
HALIDES
HALOGEN COMPOUNDS
MIXTURES
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
QUANTITY RATIO
SODIUM CHLORIDES
SODIUM COMPOUNDS
SOLUTIONS
SPECIFIC HEAT
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
THERMODYNAMIC PROPERTIES