Apparent Molar Volumes and Apparent Molar Adiabatic Compressions of Water in Some Alcohols

The ultrasonic velocities in dilute alcoholic solutions of water have been measured in the temperature range from 5 to 45 °C. The solvent alcohols used were methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 1-pentanol, and 2-methyl-2-butanol. In addition, the densities of 2-butanol and 2-methyl-1-propanol solutions of water were also measured. The apparent molar volumes and apparent molar adiabatic compressions of water in these alcohols have been evaluated. The limiting partial molar quantities are less than the molar quantities of pure water; this phenomenon is generally more pronounced for lower-chain or branched-chain alcohols. The results are discussed in connection with the hydrogen-bonding interactions, that is, the self-association of the solvent alcohols and the alcohol–water interactions.