The normal boiling point of a liquid is 350 K and Δ H_vap is 35 kJ/mol. Assume that Δ H_vap is indep — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

At normal boiling point (350 K, 1 atm): Δ G_vap = 0 and Δ S_vap = Δ H_vap/T = 35000/350 = 100 J/K·mol. At 0.5 atm (below equilibrium pressure of 1 atm): vaporization is spontaneous, Δ G_vap < 0 (B correct); vapor has larger volume and more randomness, so Δ S_vap > 100 J/K·mol (A correct). At 2.0 atm (above 1 atm): vaporization is non-spontaneous, Δ G_vap > 0 (D correct); Δ S_vap < 100 J/K·mol (C incorrect).