Investigation of the magnetic susceptibility and other physical properties of binary mixtures of organic liquids

Abstract

The work described in this thesis consists of an examination of various physical properties of complete series of binary mixtures of aromatic liquids.

The investigation was undertaken with a dual object in view: (1) To ascertain the nature of the physical or chemical changes occuring in the liquids on mixing and (2) To gain an insight into the relative suitability of the various physical properties for shewing the chemical changes which may have occured.

The binary mixtures named below have been examined: (1) Toluene and m-Cresol. (2) Aniline and m-Cresol. (3) Aniline and Nitrobenzene. (4) m-Cresol and Benzene. (5) Toluene and benzene. (6) Nitrobenzene and m-Cresol.

In each case the following five physical properties have been investigated: (1) Specific Gravity. (2) Refractive Index. (3) Heat of Mixing. (4) Specific Heat. (5) Magnetic Susceptibility, the liquids were purified very carefully, (constant boiling point and Specific gravity being the criterion of purity) and mixtures were prepared covering the whole concentration range, from one pure component to the other.

Specific gravities were measured with a 2 cc. pyknometer, refractive indices with a Pulfrich refractometer used with a temperature control, heats of mixing and specific heats by the method of mixtures, and magnetic susceptibilities with a modified form of Curie balance.

From the refractive indices, specific and molecular refractivity, dispersion, molecular dispersion, and dispersive power were calculated.

In all cases the results are tabulated and from the tables, curves are drawn in which the value of the physical property as ordinate is plotted against the composition expressed in moles % as abscissa.

It was found that (1) none of the mixtures was ideal, i,e. in all cases there was a change on mixing; and (2) the best properties for detecting changes are dispersion, heat of mixing, and magnetic susceptibility, the other properties examined not shewing very marked changes with the changes occurring on mixing.