Binary mixtures of acrylonitrile (AN) with a homologous series of secondary alcohols (2-propanol, 2-butanol, 2-pentanol, 2-hexanol, and 2-heptanol) were investigated over the temperature interval 293.15–323.15 K, to illustrate their volumetric and viscometric deviations from ideality. Experimental results reveal that, across all compositions, the excess molar volume remains positive but increases with temperature and alkyl chain of alcohol, indicating that thermal agitation and increased hydrophobic character reduce efficient packing in the liquid mixtures. Correspondingly, the viscosity deviation is uniformly negative, with its magnitude becoming more negative for alcohols of greater chain length, reflecting the dominance of weakened dipolar and hydrogen‐bond interactions that facilitate molecular slippage in mixtures containing longer alkyl tails. To describe the viscosity of the pure components, we applied a theoretical model, named significant structure theory, achieving a high degree of precision having a maximum difference of 1.734% for 2-heptanol. This highlights the effectiveness of the proposed model in predicting the viscosity behavior of pure chemicals.
