Diffusion of water in solutions of alkali metal bromides, tetraalkylammonium bromides and ammonium bromide

Journal Article · Mon Dec 01 04:00:00 EST 1986 · J. Solution Chem.; (United States)

DOI:https://doi.org/10.1007/BF00645195· OSTI ID:6488791

Easteal, A J; Woolf, L A

The diffusion coefficient of water D/sub w/ in aqueous solutions of the alkali metal bromides, tetraalkylammonium bromides (methyl, ethyl, n-propyl, and n-butyl) and ammonium bromide at 25/sup 0/C is reported for concentrations up to 2 mol-dm/sup -3/. In addition, values for D/sub w/ in 2 mol-dm/sup -3/ solutions of CsBr, KBr, NaBr, LiBr, and fully deuterated methanol, acetonitrile, and acetone have been measured for temperatures in the range 5 to 50/sup 0/C. The concentration dependence of the relative water diffusion coefficient D/sub W//D/sub 0/, where D/sub 0/ is the self-diffusion coefficient of water, has been analyzed in terms of an equation analogous to the Jones-Dole equation for relative viscosity. The B-coefficient for diffusion is well correlated with the viscosity B-coefficient. For the structure-breaking electrolytes CsBr and KBr, D/sub W//D/sub 0/ decreases rapidly with increasing temperature, whereas for the structure-makers NaBr and LiBr, the temperature dependence of D/sub W//D/sub 0/ has the same sign but is much smaller in magnitude. For the nonelectrolyte solutions, the structure-making effect decreases with increasing temperature and the temperature coefficient of D/sub W//D/sub 0/ is positive. It is apparent that, when diffusion of the solvent is being considered, the temperature must be taken into account in the classification of an electrolyte as a structure-breaker or structure-maker.

• Research Organization: Australian National Univ., Canberra
• OSTI ID: 6488791
• Journal Information: J. Solution Chem.; (United States), Journal Name: J. Solution Chem.; (United States) Vol. 15:12; ISSN JSLCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ACETONE
ACETONITRILE
ALCOHOLS
ALKALI METAL COMPOUNDS
AMINES
AMMONIUM COMPOUNDS
AQUEOUS SOLUTIONS
BROMIDES
BROMINE COMPOUNDS
CESIUM BROMIDES
CESIUM COMPOUNDS
COMPARATIVE EVALUATIONS
DEUTERIUM COMPOUNDS
DIFFUSION
DISPERSIONS
ELECTROLYTES
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
KETONES
LABELLED COMPOUNDS
LITHIUM BROMIDES
LITHIUM COMPOUNDS
LITHIUM HALIDES
METHANOL
MIXTURES
NITRILES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHYSICAL PROPERTIES
POTASSIUM BROMIDES
POTASSIUM COMPOUNDS
QUATERNARY COMPOUNDS
RUBIDIUM BROMIDES
RUBIDIUM COMPOUNDS
SODIUM BROMIDES
SODIUM COMPOUNDS
SOLUTIONS
TEMPERATURE DEPENDENCE
THERMAL DIFFUSIVITY
THERMODYNAMIC PROPERTIES
TRITIUM COMPOUNDS
VISCOSITY