Critical behavior of static properties for nitrobenzene-alkane mixtures.
We present experimental data of the isobaric heat capacity per unit volume C(p,x)V(-1) for mixtures containing nitrobenzene and an alkane (C(N)H(2N+2), with N ranging from 6 to 15) upon approaching their liquid-liquid critical points along a path of constant composition. Values for the critical amplitude A(+) have been determined. They have been combined with the previously reported ones for the leading term of the coexistence-curve width to obtain, with the aid of well-known universal relations, the critical amplitudes of the correlation length and of the osmotic susceptibility. The trends of all these critical parameters, which exhibit anomalous behavior in the low N region, are discussed in terms of particular microscopic phenomena characterizing NB-C(N)H(2N+2) mixtures. The work is completed with an analysis of the analog of the Yang-Yang anomaly in liquid-liquid criticality: the behavior of the partial molar heat capacities of the two liquid components is found to illustrate previously uncovered asymmetry effects.
Departamento de Física Aplicada, Universidad de Vigo, As Lagoas s/n, Ourense 32004, Spain.
Germán
G
Pérez-Sánchez
Patricia
P
Losada-Pérez
Claudio A
CA
Cerdeiriña
Jan
J
Thoen
D000473:Alkanes / Q000737:chemistry*; D009578:Nitrobenzenes / Q000737:chemistry*; D013696:Temperature
D000473:Alkanes; D009578:Nitrobenzenes; C036077:nitrobenzene