Amounts of 0.8 mol of PCl₅ and 0.2 mole of PCl₃ are mixed in a 1 l flask. At equilibrium, 0.4 mole o — Chemical Equilibrium Chemistry Question

💡 Solution & Explanation

Initial moles: PCl₅ = 0.8, PCl₃ = 0.2, Cl₂ = 0. At equilibrium, PCl₃ is 0.4, meaning 0.2 mol of PCl₃ formed. Thus, 0.2 mol of PCl₅ reacted and 0.2 mol of Cl₂ formed. Eq moles: PCl₅ = 0.6, PCl₃ = 0.4, Cl₂ = 0.2. Volume = 1 L. K_c = ([PCl₃][Cl₂]) / [PCl₅] = (0.4 × 0.2) / 0.6 = 0.08 / 0.6 = 0.133 mol L⁻¹. Therefore, correct answer is B.