Hanxing Zong

The vapor heat capacities of acetone-chloroform, benzene-carbon tetrachloride and benzene-ethanol binary mixtures

The vapor heat capacities of acetone-chloroform, benzene-carbon tetrachloride and benzene-ethanol binary mixtures as a function of temperature and composition have been measured under atmospheric pressure in a multicomponent vapor flow calorimeter. It was found that the heat capacities of benzene-carbon tetrachloride vapors display ideal behavior, while those of acetone-chloroform vapors demonstrate positive deviation and those of benzene-ethanol vapors, negative deviation from the ideal linear additive values. These phenomena are explained and discussed.

Excess enthalpies of n-butanol + ethyl esters

Abstract Excess molar enthalpies of n -butanol +ethyl acetate, +ethyl propionate, +ethyl n -butyrate, +ethyl n -valerate, +ethyl n -caproate have been measured at 308.15 K with a Martin-type isothermal displacement calorimeter. The UNIQUAC model is successfully used to correlate the H l m of the five binary systems.

Calorimetric determination of the vapor heat capacity of petroleum cuts

The isobaric vapor heat capacity of nine petroleum cuts, the multicomponent system, was measured as a function of temperature at atmospheric pressure by using a flow calorimeter constructed in this laboratory, and which was tested by determining the vapor heat capacity of benzene and benzene + carbon tetrachloride, ethanol + carbon tetrachloride binary mixtures with deviations of less than 1% from the literature data. The changes of the multicomponent vapor heat capacities with the temperature and some basic physical properties of the petroleum cuts were discussed and a correlation was then presented. The experimental data were also compared with the calculation results by three well-known correlations from the literature.

Experimental determination of the isobaric specific heat capacities of multicomponent vapors up to temperatures of 600 K

Abstract A new flow calorimeter has been constructed for the determination of the isobaric specific heat capacities of multicomponent vapors. It can yield reliable values over a wide temperature range with deviations of less than 1.0%. Using this apparatus, the isobaric specific heat capacities of benzene-cyclohexane, benzene-carbon tetrachloride and ethanol-carbon tetrachloride vapor mixtures have been determined under atmospheric pressure and up to 600 K. For polar mixtures, a slightly negative excess heat capacity was found, and this is explained.

Enthalpic and entropic contributions to substituent effects on the ionization of meta- and para-nitrobenzoic acids in EtOH–H2O mixtures at 298.15 K

Abstract Enthalpic and entropic contributions to substituent effects on the ionization of meta - and para -nitrobenzoic acids in EtOH–H 2 O mixtures have been examined in terms of ρ H , σ H and ρ S , σ S . The variations of ρ H and ρ S are attributed to the structural alteration of the mixed solvents.

Ionization thermodynamics of weak acids in water/DMF mixtures at 298.15 K

Abstract The enthalpies of ionization of acetic, chloroacetic, bromoacetic and iodoacetic acids in water/DMF mixtures were measured at 298.15 K with an LKB 2277 BioActivity Monitor. Solvent and substituent effects are discussed.