Pentaborane (B5H9) B5H9(l) T(K) Cp S -[G-H(Tr)]/T H-H(Tr) delta-f H delta-f G log Kf 0 100 200 298.15 151.126 184.330 184.330 0. 42.844 171.913 -30.118 300 152.298 185.269 184.333 0.281 42.780 172.714 -30.072 400 185.351 233.939 190.744 17.278 39.888 216.489 -28.271 500 190.372 275.566 203.682 35.942 36.745 260.981 -27.264 600 210.037 311.791 218.723 55.841 33.557 306.142 -26.652 700 244.346 347.030 234.537 78.745 32.465 351.697 -26.244 800 256.479 380.470 250.719 103.801 32.820 397.284 -25.940 900 267.096 411.315 266.871 130.000 33.724 442.793 -25.699 1000 275.307 439.903 282.763 157.140 35.036 488.177 -25.500 1100 280.272 466.381 298.267 184.925 36.497 533.421 -25.330 1200 284.512 490.955 313.313 213.170 37.945 578.532 -25.183 1300 288.027 513.872 327.869 241.803 39.327 623.524 -25.054 1400 290.816 535.323 341.929 270.751 40.588 668.414 -24.939 1500 292.880 555.462 355.500 299.942 41.671 713.219 -24.837