ACTIVITY MEASUREMENTS OF BISMUTH AND ANTIMONY IN LIQUID COPPER BASE BINARY ALLOYS BY THE KNUDSEN EFFUSION METHOD WITH ELECTROBALANCE.

The activity of bismuth in binary dilute solutions shows positive deviation from Raoult's law, and the activity coefficient at infinite dilution is estimated at 2. 6 at 1373 K. The activity of antimony in binary dilute solutions shows negative deviation from Raoult's law and the values are estimated at 2. 0 multiplied by 10** minus **2 at 1373 K, 1. 0 multiplied by 10** minus //2 at 1273 K and 4. 9 multiplied by 10** minus **3 at 1173 K. Activity curves of antimony at various temperatures show a crossover point at about N//S//b equals 0. 3 near the composition corresponding to intermetallic compounds.