Thermodynamic properties of vitamin C thermal degradation in wedang jeruk

Abstract

Wedang jeruk is one of Indonesia's special drinks. Wedang jeruk can be made from citrus, tea, and sugar. The purpose of this study was to determine thermodynamic properties of thermal degradation of vitamin C in wedang jeruk. Thermal degradation was carried out at 313-353 K for 90 minutes. The result shows that the enthalpy of activation ranged from 12.82 kJ/mol to 38.47 kJ/mol while entropy ranged from -0.31 kJ/molK to -0.23 kJ/molK. The enthalpy of activation indicates that degradation of vitamin C is endothermic processes. The value of enthalpy and entropy indicates the value of Gibbs-free energy is positive which means the reaction goes non-spontaneously. The harmonic temperature is higher than the isokinetic temperature. This reaction driven by entropy.