Honors & AP Chemistry · Gases
Temperature sets the average kinetic energy. Watch what that means for how fast molecules move, why their speeds spread out, and why light gases escape faster than heavy ones.
Depends only on temperature. Every gas at the same T has the same average KE.
Use R = 8.314 J/(mol·K) and M in kg/mol to get m/s.
Lighter gases effuse faster. Rearranged: M₂ = M₁ × (rate₁ / rate₂)².
Same KE, smaller m → bigger v. That single idea explains every tab on this page.
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