A vessel contains a mixture of and D2 gases. If a pin hole is made in the vessel, then — States of Matter and Gaseous State Chemistry Question

💡 Solution & Explanation

According to Graham's Law of Effusion, rate of effusion is inversely ∝ the square root of molar mass (r ∝ 1/√M). Since $H_2$ (M = 2) is lighter than D2 (M = 4), $H_2$ effuses out faster than D2. Consequently, the remaining gas mixture becomes enriched in D2 over time, increasing its mole fraction and average molecular weight. Partial pressure of both gases must decrease as gas escapes.