Thermodynamics Studies for 6-(4-chlorophenyl)-1,2,3,4-tetrahydro-4-oxo-2-thioxopyrimidine-5-carbonitrile in 60% Dimethyl Sulphoxide at Different Temperatures

Abstract

Viscometric studies for ternary mixture of 6-(4-chlorophenyl)-1,2,3,4-tetrahydro-4-oxo-2-thioxopyrimidine-5-carbonitrile in 60% dimethyl sulphoxide was carried out at different temperatures ranging between 298 and 313 K over different concentration. From viscometric data ΔG, ΔS and ΔH were evaluated. The result shows that the magnitude of ΔG and ΔH are negative while ΔS is positive showing spontaneity of reaction according to thermodynamics pointing structure breaking takes place between solute and solvent. As ΔH is negative and ΔS positive, the reaction is spontaneous at low temperatures (decreasing the magnitude of the entropy term). The thermodynamic study reveals that as concentration increases spontaneity of reaction decreases.