AbstractA new technique which permits rapid and precise measurement of vapor pressure over dilute solutions was used here to investigate the intermolecular forces of acetone molecules in several inert organic solvents. In the dilute solution of acetone mole fraction less than 0.03, acetone dimers were found to be the main species in the solvents, cyclohexane and CCl4. And no associated species of acetone were found in benzene. The strength of dipole‐dipole interactions which stabilize the acetone dimer were found comparable to that of some hydrogen bonds and also greatly influenced by solvent