Volatilization of ketones from water

The overall mass-transfer coefficients for the volatilization from water of acetone, 2-butanone, 2-pentanone, 3-pentanone, 4-methyl-2-pentanone, 2-heptanone, and 2-octanone were measured simultaneously with the oxygen-absorption coefficient in a laboratory stirred water bath. The liquid-film and gas-film coefficients of the two-film model were determined for the ketones from the overall coefficients, and both film resistances were important for volatilization of the ketones. The liquid-film coefficients for the ketones varied with the 0.719 power of the molecular-diffusion coefficient, in agreement with the literature. The liquid-film coefficients showed a variable dependence on molecular weight, with the dependence ranging from the ?0.263 power for acetone to the ?0.378 power for 2-octanone. This is in contrast with the literature where a constant ?0.500 power dependence on the molecular weight is assumed. The gas-film coefficients for the ketones showed no dependence on molecular weight, in contrast with the literature where a ?0.500 power is assumed.