Labs / Chemistry
Molecular Speeds
Every particle in a gas moves at its own speed, and together they form a lopsided bell curve. Drag up and down over the box to heat or cool the gas, swap in a heavier or lighter molecule, and watch the histogram fill in the Maxwell–Boltzmann distribution beside it.
vₚ —v̄ —v_rms —
What to try
- Heat the gas up. Does the whole curve just shift right, or does it flatten and spread out too?
- Why is the peak (most-probable speed) always to the left of the average and rms speeds — never in the middle?
- Switch from CO₂ to H₂ at the same temperature. Why do the lightest molecules race so much faster?
- What temperature and molar mass make hydrogen fast enough to escape a planet's gravity?
- Cool the gas toward 100 K. What happens to the tail of very fast particles that drive evaporation and reaction rates?