To determine the number of moles in a given mass of a substance, we use the formula:
\[ \text{Number of moles} = \frac{\text{Mass of substance (g)}}{\text{Molar mass (g/mol)}} \]
For carbon dioxide (CO2):
- Given mass: 22 g
- Molar mass: 44 g/mol
Substituting the values into the formula:
\[ \text{Number of moles of CO}_2 = \frac{22\, \text{g}}{44\, \text{g/mol}} = 0.5\, \text{mol} \]
Thus, there are 0.5 moles present in 22 g of carbon dioxide.