Viscometric method has been used to study the interaction between the weak interacting systems such as benzene-CCl₄-cyclohexane, toluene-CCl₄-cyclohexane ando- xylene-CCl₄-cyclohexane. The equilibrium constants and other thermodynamic parameters have been reported and compared with literature data.

The viscometric method can be conveniently used for studying the interaction between weakly interacting systems. The systems studied are: methanol-acetone, ethanol-acetone,n-propanol-acetone andn-butanol-acetone in carbon tetrachloride. At 25°C, the equilibrium constants for the above ternary systems are 0·22, 0·30, 0·38 and 0·52 M⁻¹ respectively. However, the heats of formation of complexes obtained by the viscometric method are high and decrease from methanol-acetone-CCl₄ ton-butanol-acetone-CCl₄.

A conductometric titration technique has been used for determining the stoichio-metry of charge-transfer complexes which ionise in polar media. The systems studied are: Iodine complexes of acetone, methyl ethyl ketone,iso-butyl methyl ketone, dimethylsulphoxide triphenyl phosphine, triphenyl arsine, triphenyl stibene, methanol, ethanol andn-propanol. The stoichiometry of the above complexes (in highly polar media) were found to be≈2:3 (except in the cases of triphenyl stibene where stoichiometry was≈1:4). The effects of temperature, concentration and dielectric constants (of the media) on conductivities of the complexes have been reported.