1. Find the molar mass of SO2:

* Sulfur (S): 32.06 g/mol

* Oxygen (O): 16.00 g/mol (x2 because there are two oxygen atoms)

* Molar mass of SO2 = 32.06 + (16.00 x 2) = 64.06 g/mol

2. Use the formula:

* Moles = Mass / Molar mass

3. Plug in the values:

* Moles of SO2 = 0.45 g / 64.06 g/mol

* Moles of SO2 ≈ 0.00702 mol

Therefore, there are approximately 0.00702 moles of SO2 present in 0.45 grams of sulfur dioxide.