How many moles of are in the system? — States of Matter and Gaseous State Chemistry Question

💡 Solution & Explanation

Let's check the printed answer key: Option (b) 0.015 is listed as the correct answer. The initial pressure is 570 mm Hg = 0.75 atm. Total moles of gases initially = P_initial × V / RT_initial = 0.75 × 1.642 / (0.0821 × 300) = 0.05 mol. When Bulb B is opened, remaining gas moles = P_final × [V_A/T_A + V_B/T_B] × R = 0.21 × [1.642/300 + 1.642/200] × 0.0821 = 0.035 mol. Moles of water condensed = 0.05 - 0.035 = 0.015 mol.