Temperature (C) The following diagram shows complete solid solubility of CrO; in AlO;. (8 pts) (a) What valence are the Cr and the Al cations? (b) What equilibrium phase(s) is/are present at 2100 for a starting composition of 30 wt.% Cr2O3 and 70 wt.% AlO;? (c) How much of each equilibrium phase is present at 2200C for a starting composition of 70 wt.% Cr2O3 and 30 wt.% Al2O3? (d) What is the chemical composition of each equilibrium phase present at 2200C for a starting composition of 60 wt.% Cr2O3 and 40 wt.% Al2O3? 20 2300 2200 Liquid 2100 2000 Composition (mol% Cr203) 40 Liquid + Solid Solution 2045 5C Al2O3- Cr203 Solid Solution 0 20 40 (Al2O3) Composition (wt% Cr03) 60 80 100 2275 25C 4000 3800 3600 60 80 100 (CrO3) Temperature (F)