What is the entropy change when 3.6 g of liquid water is completely converted into vapours at 373 K? — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

Moles of water n = 3.6 / 18 = 0.2 mol. Heat of vaporization Δ H = 0.2 * 40.85 kJ = 8.17 kJ = 8170 J. At transition temp 373 K: Δ S = Δ H / T = 8170 / 373 = 21.89 J/K.