Question

Question #b984f

Answer 1

A mole ratio consists of whole numbers because atoms and molecules react as whole particles.

If we have a reaction such as

N₂ + 3H₂ → 2NH₃

we know that 1 molecule of N₂ reacts with three molecules of H₂. The molecular ratio is 1:3.

If we multiply everything by Avogadro’s number N, we find that N molecules of N₂ react with 3 N molecules of H₂. The molecular ratio is N:3 N = 1:3.

But N molecules = 1 mol. Therefore
1 mol N₂ reacts with 3 mol H₂. The molar ratio is 1:3.

The molar ratio consists of small whole numbers because it is the same as the ratio of the numbers of reacting molecules.