ABSTRACT

Values of apparent molar volume and isentropic compressibility of symmetric and asymmetric isomers of tetrabutylammonium bromide, namely tetra-n-butylammonium bromide, tetra-iso-butylammonium bromide, tetra-sec-butylammonium bromide, di-n-butyl-di-iso-butylammonium bromide and di-nbutyl- di-sec-butylammonium bromide, in aqueous solution were determined from density and speed of sound measurements. These properties were obtained as a function of molal concentration within the range of 0.01 less than m/mol kg 1 less than 0.1 covering temperatures from 278.15 6 T/K 6 293.15. The partial molar volumes and the apparent isentropic molar compressibility at infinite dilution were calculated and their dependence on temperature examined. The results show that cations with sec-butyl chains have larger structural volumes compared to those with iso-butyl chains. In addition, cations with secbutyl chains induce smaller structural changes in their hydration shell than the others.

Compounds

#	Formula	Name
1	C16H36BrN	tetrabutylammonium bromide
2	C16H36BrN	tetra-iso-butyl ammonium bromide
3	C16H36BrN	tetra-sec-butyl ammonium bromide
4	C16H36BrN	N-butyl-N,N-bis(2-methylpropyl)-1-butanaminium bromide
5	C16H36BrN	N-butyl-N,N-bis(1-methylpropyl)-1-butanaminium bromide
6	H2O	water

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Constraint	Phase	Method	#Points
POMD	1 6	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	40
POMD	1 6	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid Frequency, MHz; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	45
POMD	6 2	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 2; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	40
POMD	6 2	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Molality, mol/kg - 2; Liquid	Pressure, kPa; Liquid Frequency, MHz; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	45
POMD	6 3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 3; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	36
POMD	6 3	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Molality, mol/kg - 3; Liquid	Pressure, kPa; Liquid Frequency, MHz; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	50
POMD	4 6	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 4; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	40
POMD	4 6	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Molality, mol/kg - 4; Liquid	Pressure, kPa; Liquid Frequency, MHz; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	45
POMD	6 5	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 5; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	40
POMD	6 5	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Molality, mol/kg - 5; Liquid	Pressure, kPa; Liquid Frequency, MHz; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	50

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Partial molar volume and isentropic compressibility of symmetrical and asymmetrical quaternary ammonium bromides in aqueous solution

Moreno, N.[Nicolas], Buchner, R.[Richard], Vargas, E. F.[Edgar F.]

ABSTRACT