Enthalpy, entropy and free energy of activation have been calculated from the experimental values of density and viscosity of binary liquid mixtures of L-Alanine and L-Glutamine with water at different temperature. Densities and viscosities of liquid mixtures plays an important role in finding their heat content, mass transport, fluid flow and molecular structures etc. excess molar enthalpy of activation and free energy of activation are useful in understanding the nature of intermolecular interactions, dispersion forces and the extent of hydrogen bonding between two liquids. All the mixtures exhibited endothermic enthalpies, entropy of activation are negative over all composition range, its values suggesting weak molecular interaction, dispersive forces and extend of hydrogen bonding between constituent molecules.