Rate constant for the base catalyzed hydrolysis propyl hexnoate was determined volumetrically in water-n-propanol mixture for the composition varying from 30 to 70% (v/v) at different temperature ranging from 200C to 400C. The initial slow but sharp decrease in rate with gradual addition organic co- solvent in the reaction media and with increasing temperature of reaction has been explained on the basis of salvation and desolvation of initial and transition state to different extent. The Iso-composition activation energy (EC) energy for same solution increases as propanol content increases while Iso- Dielectric activation energy (ED) with decrease as the dielectric constant of the solvent increases. The trends of variation of numbers of water molecule associated with activated complex increases with increasing temperature from 200C to 400C tells about the fact that in presence of protic solvent(propanol) in reaction media, the bimolecular mechanistic path of reaction changed to unimolecular. The enhancement in ?G* with simultaneous increase in (?H*) and (?S*) values of the reaction concluded that the reaction is enthalpy controlled.
Cite this article:
A. K. Singh, Arjuman Bano. Kinetics and Solvent effect on Aquo-dipolar protic organic-solvent system of Hexanoate ester. Asian J. Research Chem. 2019; 12(6):341-344. doi: 10.5958/0974-4150.2019.00064.6