%0 Journal Article
%T ENTROPY OF MIXING OF TWO COMPLEX FORMING BINARY LIQUID ALLOYS
%A S. K. Chakrabarti
%J International Journal of Chemical Sciences and Research
%D 2011
%I 
%X There are a large number of binary liquid alloys which exhibit interesting behaviour as a function of concentration as regards the thermodynamic properties. In the present work two binary molten alloys are considered e.g. Cu-Sn and Cd-Mg in which complexes are formed as revealed from their liquidus lines. The former alloy shows anomaly in its thermodynamic properties of mixing. On the other hand, the alloying behaviour of the latter one is symmetric around the equi-atomic composition. But so far as entropy of mixing (SM) is concerned copper-tin liquid alloy also shows symmetry about equi-atomic composition. Here the quasi-lattice chemical model has been used for computation of the values of SM of these alloys for different concentrations of the ingredients. For each alloy calculations are started with the expression for excess free energy of mixing (xsGM ) according to this model and the values of different interaction parameters (¦Øij) are primarily found out from the experimental data of xsGM for several concentrations of the constituent species. Putting these values of ¦Øijthe free energy of mixing (GM) is calculated for various concentrations and then compared with its observed values both numerically and graphically. Accordingly, a modified set of values of ¦Øij has been considered and the calculations are repeated. In this way by the method of successive approximation the values of the interaction parameters have been ascertained and thereby the set of values of GM. Similarly, the expression for heat of mixing (HM) is taken into account and the temperature derivatives of the said interaction parameters are ascertained from the observed values of HM for different concentrations by such successive approximation method. Finally, SM has been computed on using the standard thermodynamic relation from the sets of values of GM and HM thus obtained. The results explain the observed symmetry in the entropy of mixing of the present alloys.
%K Binary liquid alloys
%K Quasi-lattice chemical model
%K Entropy of mixing.
%U http://www.ijcsr.co.in/Documents/Volumes/Vol%20I%20issue%201/ijcsr2011010103.pdf