Adsorption of cresols on molybdenite

A spectrophotometric method has been developed to determine individual cresols as well as mixed cresol isomers. The cresols were determined by the yellow colour produced by nitrocresols in an alkaline medium. The optimum wavelength was found to be at 395 mm. Adsorption of p-cresol on synthetic molybdenite at different pH, as well as at different cresol concentrations, was determined. The adsorption is found to be L2 type of Giles. Adsorption studies of p-cresol on molybdenite were also done at different temperatures. A thermodynamic analysis has been made of the system p-cresol molybdenite. Adsorption is found to be wholly physical. The low entropy values obtained for the above system reveal the more orderly structure of the adsorbed species. (K.V. Viswanathan and K.K. Majumdar, Babha Atomic Research Centre, Bombay)