Solutions : II 179 7.7 The vapour pressure of copper over Cu-Fe alloys at 1550C (1823 K), as a function of composition, is given below. 1.0 0.792 0.476 0.217 Xcu cu (mm Hg) 0.547 0.486 0.449 0.399 (Poul 72.93 64.79 59.86 53.20) Calculate the activity of iron at cu = 0.217, assuming that the alpha-func- tion is the same for both fron and copper at this concentration at 1550c (1823 k). Solutions : II 179 7.7 The vapour pressure of copper over Cu-Fe alloys at 1550C (1823 K), as a function of composition, is given below. 1.0 0.792 0.476 0.217 Xcu cu (mm Hg) 0.547 0.486 0.449 0.399 (Poul 72.93 64.79 59.86 53.20) Calculate the activity of iron at cu = 0.217, assuming that the alpha-func- tion is the same for both fron and copper at this concentration at 1550c (1823 k)