Document Type : Research Paper
The thermodynamic functions such as enthalpy (H), Gibbs free energy (G) and entropy (S) of
Pyrazole was theoretically studied at 5 different temperatures 25, 30, 35, 40 and 45°C by using
Gussian o3, software. First, the structural optimization of isolated Pyrazole was done in the gas phase
by appling the Density Functional Theory (B3LYP) level with 3-21G, 6-31G and 6-31+G(d) basis
sets. Moreover, vibrational frequencies were calculated in gas phase on the optimized geometries at
the same level of theory to obtain enthalpy, Gibbs free energy and entropy at 5 different
temperatures.Finally the temperature effects on the thermodynamic functions were discussed.