Perturbed hard fluid theoretical analysis of the effects of solvation on the thermodynamics of a hemiketal formation reaction

Abstract

The effects of temperature and pressure on the equilibrium reaction of acetone and methanol to form a hemiketal (2-methoxy-2-propanol), when dissolved in either tetrahydorfuran or diethyl ether, are analyzed using the perturbed hard fluid (PHF) model. Experimental global reaction thermodynamic results (ΔG,ΔH,ΔS,ΔV,ΔU,ΔA) are obtained from pressure- and temperature-dependent calibrated Raman peak area measurements. The PHF theoretical analysis separates the effects of repulsive and attractive solute–solvent interactions by combining hard sphere fluid and van der Waals mean field approximations. The results offer a critical test of these approximations and elucidate the way in which the balance of repulsive and attractive interactions contribute to each reaction thermodynamic function.