1. What is the volume (L) of 3.01×10 23 molecules of carbon monoxide (CO)?

2. How many molecules of SO2 are present in 0.45 grams of sulfur dioxide?

3. What volume (L) will the molecules of SO2 in question 2 occupy?

assuming STP,

#1 3.01/6.02 * 22.4
#2 0.45/64.06 * 6.02*10^23
#3 0.45/64.06 * 22.4

better review the topic some more.