By using the following reactions, calculate the heat of formation of pentane (c5h12) gas from carbon and hydrogen gas. c (s) + o2 (g) co2 (g), h = 395 kj/mol h2 (g) + 1/2o2 (g) h2o (l), h = 285 kj/mol c5h12 (g) + 8o2 5co2 (g) + 6h2o (l), h = 3.54 × 103 kj/mol

Asubstance is held in an open container. its particles move past one another at random speeds but do not leave the container. heat is removed from the system, and the particles slow down. when enough heat is removed, the particles no longer have enough speed to overcome the weak attractive forces between them. when this happens, the substance enters its solid state. the process described above is known as .