The solubility (crystallization) of n-alkanes and mixtures (paraffins) in unassociated (chloroalkanes, toluene, hexane) and associated (ketones, alcohols, carboxylic acids) solvents and in binary mixtures of these solvents was investigated. The values of the macroscopic dipole moment (arbitrary polarity) were determined for the first time for acetone and its homologs, up to methyl hexyl ketone, for C-4-C-7 aliphatic alcohols, and for carboxylic acids - from butyric to caprylic. Using the dependences of the arbitrary polarity on the molecular weight and molar refraction of the solvents, the polarity values were calculated for water, methanol, formic acid, and other associated substances. The mechanism of the increase in the solubility of water, glucose, and glycine with a decrease in the difference between the polarity of the solvent and the dissolved substance was demonstrated.