An-Najah Staff

The dynamic shear viscosity of the binary liquid mixture methanol - cyclohexane for different temperatures and concentrations is measured using digital viscometer with UL adapter. Shear viscosity anomaly is clearly observed near the critical temperature T_c = 45.2 ℃ and the critical concentration X_c = 30% by weight of methanol. The specific heat at constant pressure of the critical mixture methanol – cyclohexane was calculated using two scale factor universality. The dynamic scaling theory of Ferrell and Bhattacharjee is applied to the data of the ultrasonic absorption coefficients α_c at different frequencies. The linear relation of  α_c/ ƒ²  versus ƒ^(-1.06)  was obtained. The adiabatic coupling constant g, isobaric thermal expansion coefficient α_p and diffusion coefficient D were calculated. The experimental values of α(X_c ,T) / α(X_c ,T_c)   were plotted as a function of the reduced frequency ω* and it showed a good agreement with the theoretical scaling functionF(ω*)presented by Ferrell and Bhattacharjee.