Thermodynamics of n-component systems (n<6): Calorimetric measurements and estimation of enthalpies of formation

The enthalpies of formation (Delta(mix)H(m) degrees) of the [Bi+Cd+Ga+Zn], [Bi+Cd+Ga+In+Zn] and [Bi+Cd+Ga+In+Sn+Zn] liquid alloys were measured at 730 K by additions of a solid metal (Bi, Cd, In, Sn) to the equimolar sub systems [Bi+Ga+Zn], [Cd+Ga+Zn], [Bi+Cd+Ga+Zn], [Cd+Ga+In+Zn], [Cd+Ga+In+Sn+Zn], [Bi+Cd+Ga+In+Zn]. Simultaneously, these enthalpies (Delta(mix)H(m) degrees) were calculated by using the Hoch-Arpshofen (HA) model and published data of the enthalpies of formation of the limiting binary systems. The agreement between calculated and measured values is good in respect of the accuracy (i) of the experimental technique (direct calorimetry) and (ii) of the thermodynamic data of the sub-systems. Thus, the HA model allows the excess molar thermodynamic functions of formation of the six-component liquid alloys to be correctly predicted.