A modified Flory theory along with the Auerbach and Altenberg relations has been employed for the computation of ultrasonic velocity of three quaternary liquid mixtures and a comparative study of all the three relations has then been carried out.

The present investigation comprises of theoretical evaluation of acoustic non-linearity parameter,B/A for equimolar binary mixtures, viz. chlorobenzene or 1-chloronaphthalene with a series of normal alkanes (n-C_n,n = 6, 8, 10, 12, 14, 16), and with a series of highly branched alkanes (br-C_n,n = 6, 8, 12, 16), viz. 2,2-dimethylbutane (br-C₆), 2,2,4-trimethylpentane (br-C₈), 2,2,4,6,6-pentamethylheptane (br-C₁₂) and 2,2,4,4,6,8,8-heptamethylnonane (br-C₁₆). Tong and Dong method, thermoacoustical method, Hartmann relation and Ballou relation have been employed to evaluateB/A. A comparative study ofB/A values obtained from the aforementioned methods has been made. The results are discussed on the basis of structural orientations of normal and branched alkanes.