Question

How many moles of O2 are there in 1.20 × 1022 oxygen molecules ?

Answer 1

1.20 × 10²² molecules of oxygen

One mole of oxygen contains 6.022 × 10²³ molecules.

1.20 × 10²² molecules of oxygen contain = 1.20 × 10²² / 6.022 × 10²³ = 0.01099 moles.

Hence, 1.20 × 10²² molecules of oxygen contain 0.0199 moles of oxygen.