Component interactions in aqueous acetone

νmax and εmax for the n–π* transition of acetone in aqueous solution do not vary monotonically with acetone concentration. The Klotz-Worley R parameter for these solutions shows a maximum at 0.05 x2 whereas carbonyl infrared intensities are a linear function of acetone concentration. Hydrophobic hydration of acetone is proposed in the initial region with direct molecular interaction at approximately 0.20 and 0.45 x2.