Iron Sulfide, Marcasite (FeS2) Fe1S2(cr) T(K) Cp S -[G-H(Tr)]/T H-H(Tr) delta-f H delta-f G log Kf 0 0. 0. INFINITE -9.753 -163.782 -163.782 INFINITE 100 19.269 7.576 99.375 -9.180 -165.012 -162.658 84.964 200 49.399 31.380 59.227 -5.569 -166.454 -159.685 41.705 298.15 62.390 53.865 53.865 0. -167.360 -156.159 27.358 300 62.554 54.251 53.866 0.116 -167.375 -156.090 27.178 400 69.169 73.244 56.411 6.733 -172.579 -152.034 19.854 500 72.447 89.075 61.407 13.834 -176.187 -146.504 15.305 600 74.568 102.472 67.163 21.185 -179.092 -140.283 12.213 700 76.959 114.139 73.058 28.757 -181.539 -133.617 9.971 800 78.668 124.569 78.857 36.569 -183.764 -126.619 8.267 900 80.718 133.953 84.466 44.538 -292.337 -117.177 6.801 1000 82.764 142.563 89.851 52.712 -292.623 -97.707 5.104 1100 84.810 150.547 95.010 61.091 -293.630 -78.151 3.711 1200 86.860 158.014 99.952 69.674 -293.910 -58.568 2.549 1300 88.910 165.048 104.692 78.463 -292.370 -39.018 1.568 1400 90.960 171.712 109.243 87.456 -290.740 -19.589 0.731