To take into account the nonequilibrium between the temperatures (electronic, relation, vibration, translation) in plasmas, the partition functions are modified. Then they are used to determine the concentration in a Gibbs free energy minimization method adapted to a multi-temperature plasma. Their influence on the results for different temperature hypotheses is quantified. The composition and thermodynamic properties of an Ar-H-2 mixture are given and discussed for different temperature nonequilibria.