The number of gram molecules of oxygen in 6.02 ×10²⁴ CO molecules is

$6.02\times {10}^{23}\text{ molecules of }\mathrm{CO}=1\text{ mole of }\mathrm{CO}$

$6.02\times {10}^{24}\mathrm{CO}\text{ molecules }=10\text{ moles }\mathrm{CO}$

= 10 g atoms of O = 5 g molecules of O₂