Role of a secondary alcohol (Propan-2-ol) in affecting the kinetics and the thermodynamic extensive properties of the acid catalysed solvolysis of iso-butyl formate has been highlighted by studying the kinetics of the reaction in different aquo-propan-2-ol reaction media having 20 to 80% (v/v) of propan-2-ol and at five different temperatures rising from 20 to 40°C at interval of 5°C It was found that with increase in Jemperature of the reaction from 20 to 40°C from 0.172 to 1.344 molecules of water are associated with the activated complex and from this, it is inferred that mechanistic path followed by the reaction in presence of propan-2-ol is changed from bimolecular to unimolecular. The depletion and enhancement observed respectively in iso-composition and iso-dielectric activation energies reveal that the transition state is solvated and initial state is desolvated with addition of propan-2-ol in reaction media. Almost unity value of the slope of the plots of log k values against log [H+] values shows that the reaction follows AAC2 mechanism. From the values of iso-kinetic temperature, which comes to be 287, it may be concluded that in water-propan-2-ol reaction media, the reaction follows Barclay-Butler rule and there is weak but acceptable interaction between solvent and solute in aquo-propan-2-ol reaction media