  The generalized Gibbs free energy and enthalpy is derived in the framework of
nonextensive thermodynamics by using the so-called physical temperature and the
physical pressure. Some thermodynamical relations are studied by considering
the difference between the physical temperature and the inverse of Lagrange
multiplier. The thermodynamical relation between the heat capacities at a
constant volume and at a constant pressure is obtained using the generalized
thermodynamical potential, which is found to be different from the traditional
one in Gibbs thermodynamics. But, the expressions for the heat capacities using
the generalized thermodynamical potentials are unchanged.

Statistical Mechanics;Classical Physics