Health & Environmental Research Online (HERO)


Print Feedback Export to File
7934261 
Journal Article 
MOLAR EXCESS HEAT-CAPACITIES AND VOLUMES FOR MIXTURES OF ALKANOATES WITH CYCLOHEXANE AT 25-DEGREES-C 
Jimenez, E; Romani, L; Andrade, MIP; Rouxdesgranges, G; Grolier, JPE 
1986 
Yes 
Journal of Solution Chemistry
ISSN: 0095-9782
EISSN: 1572-8927 
15 
11 
879-890 
English 
WOS:A1986F205000001 
Molar excess volumes VE at 25°C have been determined by vibrating-tube densimetry, as a function of mole fraction x for different series of an alkanoate (H2m+1CmCOOCnH2n+1)+cyclohexane. Three types of alkanoates were investigated, i.e., methanoates (m=0, with n=3 and 4), ethanoates (m=1, with n=2, 3, and 4) and propanoates (m=2, with n=1, 2, and 3). In addition, a Picker flow calorimeter was used to obtain molar excess heat capacities CpE at constant pressure at the same temperature. VE is positive for all systems and rather symmetric, with VE (x=0.5) amounting to almost identical values in a series of mixtures containing an alkanoate isomer of same formula (say C4H8O2, C5H10O2, or C6H12O2). The composition dependence of CpE is rather unusual in that two more or less marked minima are observed for most of the mixtures, especially when the alkanoate is a methanoate or an ethanoate. These results are discussed in terms of possible changes in conformation of both the ester and cyclohexane. 1986 Plenum Publishing Corporation. 
alkanoate + cyclohexane; Binary organic mixtures; conformational changes; densities; heat capacities; molar excess heat capacities; molar excess volumes