In this book a comprehensive study on the effect of hydrotropes such as sodium benzoate, sodium salicylate, tri-sodium citrate and urea on the solubility and mass transfer coefficient of a series of aromatic esters such as benzyl acetate, benzyl propionate, benzyl butyrate, benzyl benzoate and benzyl salicylate has been carried out. The influence of a wide range of hydrotrope concentration and different temperatures on the solubility of aromatic esters is presented. The influence of different hydrotrope concentrations on the mass transfer coefficient of esters has been ascertained. Data on various aspects of hydrotropic study on the solubility and mass transfer coefficient for a series of aromatic esters have been provided for the first time. The experimental solubility data for various solutes at different temperatures have been analyzed using the modified Setschenow equation. To propose a possible mechanism of hydrotropic phenomenon, the solution properties of hydrotropes like density and viscosity have been determined for a range of hydrotrope concentrations. The implications of the study have been fully discussed and the scope for future research has been suggested.