The thermodynamic quantities in a dusty plasma gas display a strong nonlinear dependence on the grain charge. Due to the presence of charge correlations, relations between various quantities are very different than in ail ordinary plasma. The entropy in such a plasma behaves very differently than in ail electron-ion plasma. The origin of such a difference is traced to the nonlinear dust potential. The dependence of the specific heat on the grain charge also displays strong grain charge dependence. Further. it is demonstrated that the charge fluctuation is the prime source of irreversible entropy generation in a dusty plasma environment.