The Fastest Diffusing Gas in a Flask
Which gas will diffuse the fastest when the stopper is removed from the flask?
When the stopper is removed, which gas among CH₄, O₂, C₂H₅, and N₂ will diffuse the fastest?
Answer:
When the stopper is removed, CH₄ (methane) will diffuse the fastest among the four gases in the flask.
When considering the rate of diffusion for gases, we can use Graham's Law of Effusion, which states that the rate of diffusion of a gas is inversely proportional to the square root of its molar mass. In other words, lighter gases diffuse faster than heavier gases.
Let's compare the molar masses of the four gases: CH₄ (methane), O₂ (oxygen), C₂H₅ (ethyl radical), and N₂ (nitrogen).
- CH₄: 12 (C) + 4 (H) = 16 g/mol
- O₂: 16 (O) × 2 = 32 g/mol
- C₂H₅: 2 (C) × 12 + 5 (H) = 29 g/mol
- N₂: 14 (N) × 2 = 28 g/mol
Based on the molar masses, CH₄ has the lowest molar mass at 16 g/mol. Therefore, when the stopper is removed, CH₄ (methane) will diffuse the fastest among the four gases in the flask.