Studies of viscosity of binary liquid mixtures containing bromoalkanes and some hydrocarbons

Viscosities (η) of binary mixtures between some polar aliphatic molecules viz. 1-bromopropane, 1-bromobutane and 1-bromopentane and nonpolar hydrocarbons viz. cyclohexane, benzene, 1, 4-dimethylbenzene and 1,3,5-trimethylbenzene have been measured at 308.15 K in the whole concentration range. Deviations from ideal mixture viscosities (Δη) for all the systems have been evaluated from the viscosity data. Δη values for all the binary systems are negative except for 1-bromopropane + 1, 4-dimethylbenzene binary mixture which has a few positive values beyond the equimolar mixture, and for 1-bromopropane  + 1, 3, 5-trimethylbenzene system, these are positive except a few negative values at lower mole fractions of the hydrocarbon. The mixture viscosities (η) have been analysed on the basis of several equations such as Grunberg-Nissan, Hind-McLaughlin-Ubbelohde and Katti and Chaudhary. The strengths of molecular interactions in the binary mixtures studied are discussed on the basis of variations in Grunberg-Nissan parameter (d). It is suggested that molecular interactions are dipole-induced dipole type between components of binary mixtures and the strength of interactions increases with increase in polarizability of aromatic hydrocarbons.