Calculate how many moles in 4.51 x 10^24 molecules of NH3

Answer 1

To convert molecules to moles, we need to use Avogadro's number: 6.02 x 10^23. Avogadro's number tells us how many "things" are in one mole of that "thing". This is the same idea with the concept of a "dozen". A dozen eggs means we have 12 eggs. A mole of eggs would be 6.02 x 10^23 eggs.

In this question, we can ask, "how many dozens of molecules are in 4.51 x 10^24 molecules?" Intuitively, we would just divide by 12 to calculate how many dozens that is. Likewise, we can divide by Avogadro's number to determine how many moles we have.

4.51 x 10^24 molecules / 6.02 x 10^23 = 7.49 mol NH3