Water-DMSO Co–Solvent effect and kinetics of acid catalyzed Hydrolysis of butyl formate and Influence on Activation Parameters

The acid catalyzed hydrolysis of butyl formate in presence of 0.1N-HCI in water and the presence of water-DMSO mixture containing up to 30-70% (v/v) was studied over the temperature ranging from 20-400C. The rate of reaction decreases with decrease of water content of the solvent mixture and reached minima at about 70% of organic solvent. The number of water molecule associated with activated complex was showing decrease in trend with increase of temperature, is an indication of change in mechanism from unimolecular to bimolecular in reaction media. The parameters of thermodynamic activation were also calculated and discussed in terms of solvent effect with help of plots of ΔH* versus ΔS*, the isokinetic temperature was calculated and found to be greater than 300.