Calculate the change in the molar entropy of a perfect gas when it is compressed isothermally from a pressure of 1 bar to 10 bar.

Calculate the change in the standard molar entropy of hydrogen chloride, HCl, gas when it is heated from a temperature of 20°C to 30°C.  The standard molar constant-pressure heat capacity of hydrogen chloride is 29.1 J K^–1 mol^–1.

The standard enthalpy of sublimation of carbon dioxide is 26.2 kJ K^–1 mol^–1 at 298.15 K.  Calculate the standard entropy of sublimation at this temperature.

The boiling temperature of ethylbenzene is 136 °C.  Use Trouton's rule to estimate the enthalpy of vaporization of ethylbenzene at this temperature.

Calculate the change in entropy when exactly 1 mol of solid iodine, I₂, at a temperature of 360 K is heated at constant pressure to produce liquid iodine at a temperature of 410 K.  The constant pressure molar heat capacity of solid iodine is 54.44 J K^–1 mol^–1 and of liquid iodine is 80.67 J K^–1 mol^–1.  The melting temperature of iodine is 387 K, and the molar enthalpy of fusion of iodine is 7.87 kJ mol^–1.

At low temperatures, the heat capacity of solid chlorine, Cl₂, follows the Debye T³ law, C_p,m = a T³, with a = 1.24 ´ 10^–3 J K^–4 mol^–1.  Estimate the molar entropy of solid chlorine at 10 K.

Which of the following conditions is necessary for a reaction to be spontaneous?

A hypothetical system consists of 5 molecules and 2 quanta.  What is the number of possible arrangements?

For a spontaneous change in a system at constant temperature and pressure, which of the following statements is true?

Which of the following statements is always true for a system at equilibrium under conditions of constant temperature and pressure?