∆ S Universe = ∆ S Total = ∆ S Sys + ∆ S Surr > 0. The Second Law of Thermodynamics in Terms of EntropyĪs per the second law of thermodynamics, the total entropy of the system and its surroundings (universe) increases spontaneously. So, we can say that the entropy for any substance increases with temperature. When the temperature is high, the kinetic energies of atoms are also higher than at lower temperatures. Increasing the temperature of a substance will result in more movements of the particles in solids and more rapid movements of the particles in liquids and gases.

The temperature of a substance is proportional to the average kinetic energy of its particles. The disorder of a system is related to the phase it is in.įor a crystalline solid substance, the entropy should be the lowest (most ordered), and the gaseous state is the state of the highest entropy.Įntropy changes are expressed as heat divided by temperature, so the units of entropy are calories per degree (cal deg -1 ) or Joules per Kelvin (JK -1 ). A higher value of entropy means there is a high value of disorder. Entropy is the degree of disorder of a system.

Highest absolute molar entropy