The enthalpies of tetraethyl- and tetrabutylammonium bromides solution in water and highly aqueous water formamide (FA) mixtures were measured at 277.15, 288.15, 313.15, 319.15 and 328.15 K. The standard enthalpies of solution are obtained and compared with previously determined values at 298.15 K. Heat capacities of solution were computed. Enthalpic and heat capacity coefficients of solute FA pair interactions were calculated. The heat capacity of methylene group interaction with FA was found to be negative, whereas the heat capacity of bromide ion FA interaction appeared to be positive. The free energy and entropic coefficients of tetrabutylammonium bromide FA interaction coefficients were estimated and compared with those for other non-electrolytes. It has been found that the interaction between two hydrophobic species is the entropic origin which is in agreement with classical models of hydrophobic interaction. In contrast, the interaction of tetrabutylammonium bromide with FA is the enthalpic origin, it being repulsive at all temperatures studied.
Compounds
#
Formula
Name
1
H2O
water
2
CH3NO
formamide
3
C8H20BrN
tetraethylammonium bromide
4
C16H36BrN
tetrabutylammonium bromide
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.