Problem #4 (5 points) Step by step, use Gibbs Phase Rule and Lever Rule to predict the phase changes of a compound (composition is equal to point A) along with the temperature decrease from point A to 1200C. 1900 T (C) 1800 1830 A 1700 BT+L 1612 1600 1600 1563 Liquid T+L B.T+hBT 1500 1460 428 CBT+L 1400 -BT+L 1357 BT+CBT 1322 1317 1300 CBT+BT2 BT2 BT+T + BT 1210 1200 CBT+BT, 33.3 40 B.T 50 60 70 80 BT BT BT, BT4 90 1000 Mole % TT