плотность

Concentrated water-alkaline mixtures of sodium and potassium borohydrides and borates are used as fuel and a hydrogen source in hydrogen power engineering, including low-temperature fuel cells. The performance of such mixtures is determined by their physicochemical properties. An algorithm to calculate the density, viscosity, and specific electric conductivity of mixed solutions of the five-component water + salt system (Na,K)BH₄ + (Na,K)BO₂ + (Na,K)OH + H₂O based on the quasiadditivity of these properties is proposed. The concentration-temperature dependences of the density, viscosity, and specific conductivity of aqueous KOH, NaOH, KBO₂, NaBO₂, NaBH₄, and KBH₄ solutions of any composition in a temperature range of (0 to 60)°C and the whole concentration range are described mathematically. The technique and algorithm of calculation have been verified by comparison with measured properties.

The information on volumetric properties for a following most often of used aprotic solvents acetonitrile, γ-butirolactone, 2,5-dimethyltetrahydrofurane, 1,2-dimetoxyethane, methyl acetate, 2-methyltetrahydrofurane, nitromethane, propylene carbonate, sulfolane, tetrahydrofurane and thionylchloride are considered. The temperature dependencies of density, specific and molar volumes, structural radiuses of molecules of solvents and coefficients of packaging of molecules of solvents are described.