What is the pressure of gas in the cylinder after 1 h? — States of Matter and Gaseous State Chemistry Question

💡 Solution & Explanation

The leak rate equation is -dP/dt = k(P - P_ext). At t = 0, P = 20, P_ext = 1, so 0.001 = k(20 - 1) = 19k → k = 0.001 / 19 s^-1. Integrating: ln[(P - 1)/(20 - 1)] = -kt → ln[(P - 1)/19] = - (0.001/19) × 3600 = -360/19 ≈ -18.9. This means (P - 1)/19 = e^-18.9 ≈ 0, so P ≈ 1 atm. However, the printed answer key lists (c) 1.5 atm as correct.