Chemical equilibria. Part III. Dehydrogenation of pentan-1-ol, pentan-2-ol, and 3-methylbutan-2-ol

Abstract

Equilibrium constants for the systems containing pentan-1-ol + pentanal (I), pentan-2-ol (II)+ pentan-2-one, and 3-methylbutan-2-ol (III)+ 3-methylbutan-2-one have been calculated from measurements of the compositions of mixtures formed when the vapours were passed with hydrogen over a catalyst held at a measured temperature. Equations expressing the changes in enthalpy and entropy of the reactions were derived from the equilibrium constants at several temperatures with the aid of heat capacity data. By coupling these changes with other thermodynamic data the standard enthalpies of formation (298·15 K) of the liquids were calculated to be (I)–268·2, (II)–366·4, and (III)–369·9 kJ mol^–1, and the standard entropies (298·15 K) of the liquids were calculated to be (I) 275·6, (II) 256·1, and (III) 246·1 J K^–1 mol^–1.