Equal number of moles of O₂, Cl₂, and H₂ are enclosed in a container at room temperature. If the container leaks, then?

H₂ will effuse out first

Cl₂ will effuse out last

O₂ will effuse out second

All will effuse out at the same time but with different rates

All gases will start effusing at the same time, but the rate of effusion depends on their molar mass (Graham’s Law).

Lighter gases like H₂ effuse faster than heavier ones like Cl₂.