Vapor-Liquid Equilibria and Density Measurement for Binary Mixtures of Benzene + Nonane, Methylbenzene + 1,2-Dimethylbenzene, 1,3-Dimethylbenzene + 2,3,4,5-Tetrahydrothiophene-1,1-dioxide (Sulfolane), 1,2-Dimethylbenzene + Sulfolane, 1,2-Dimethylbenzene + N-Methylformamide (NMF), 1,3-Dimethylbenzene + NMF, and 1,4-Dimethylbenzene + NMF from (333.15 to 353.15) K at Vacuum Conditions