The molecules of which gas have the greatest velocity at 120°C?

Question

A. O2
B. CO2
C. NH3
D. Cl2

Answer 1

If you have a fat (heavy--really big) dog and thin (skinny) dog, which one can move faster? It works the same way with molecules. The heavier ones move slower than the lighter ones.

Answer 2

So would the answer be NH3 since its molar mass is 17 vs 32 (o2), 44 (CO2), and 70 (Cl2)

Answer 3

I would choose NH3.