Calculating critical exponents of the phase-equilibrium curve for liquid-vapor aqueous solutions of aliphatic alcohols

摘要

Based on previously obtained experimental data corresponding to the points of liquid-vapor phase transformations in aqueous solutions of aliphatic alcohols (methanol, ethanol, n-propanol), we plot the temperature dependence of the density of liquid and vapor phases along the curve of their coexistence and in the critical region. It is established that the power functions P1,v = Pc (1 ± B_0 τ~(β0) } + B_1 τ~(β1) ± B_2 τ ~(β2)) and (P1 - Pv)/2Pc = B0 τ β0 + B2 τ β 2adequately describe the dependence of the lower density of solutions ω = (ρ_(l,p) - ρ_c)/ρ_c on reduced temperature τ = (T _c - T)/T _c, the alcohol concentration, and the number of carbon atoms (in a molecule of alcohol) in the two-phase region and in the vicinity of the critical point at critical index β0 = 0.365 ± 0.002 and B 0 = (2.471-2.803) ± 0.005.