Phosphoric Acid (H3PO4) H3O4P1(l) T(K) Cp S -[G-H(Tr)]/T H-H(Tr) delta-f H delta-f G log Kf 0 100 200 298.15 145.047 150.775 150.775 0. -1271.663 -1123.597 196.849 300 145.603 151.673 150.777 0.269 -1271.627 -1122.678 195.476 315.500 150.273 159.125 151.005 2.562 CRYSTAL <--> LIQUID 400 175.728 197.687 156.848 16.335 1269.114 1073.263 140.154 500 205.853 240.135 169.306 35.414 -1263.169 -1024.930 107.074 600 235.978 280.330 184.486 57.506 -1254.423 -978.057 85.147 700 266.102 318.968 200.954 82.610 -1242.867 -932.871 69.612 800 296.227 356.468 218.059 110.726 -1228.486 -889.534 58.081 900 326.352 393.097 235.480 141.855 -1211.263 -848.169 49.226 1000 356.477 429.041 253.044 175.997 -1191.183 -808.875 42.251