Densities,molar volumes,and surface tensions of Na-K-Cs ternary alloys along the two sections containing the eutectic alloy

The densities, molar volumes, and surface tensions of 21 ternary alloys of the Na-K-Cs system have been determined in the temperature range 293–453 K for the two sections directed to the Cs and K vertices and containing the eutectic alloy. The polytherms of these parameters for the Na_0.129K_0.435Cs_0.436 eutectic alloy in the temperature range 200–460 K are described by linear equations and their values at 373 K are determined to be 1406 kg m^?3, 54.62 × 10^?6 m³ mol^?1, and 77.0 mN m^?1, respectively. The isotherms of molar volumes of the ternary alloys in both sections obey the additivity rule; in the low-concentration range, cesium exhibits high surface activity.