What volumes will each of the following occupy at STP?

a. 1.80 x 10^24 molecules of SO3
b. 7.5 mol C2H6
c. 25.2 grams chlorine

2 answers

You need to know the following for gases at STP. ONe mole will occupy 22.4 L and will contain 6.022E23 molecules. Those two facts will work almost any simple gas problem you have concerning volume and number of molecules.
is this right for a. 1.80 x 10^24 molecules of SO3(1 mol SO3/6.022E23)(22.4L/1 mol)? but then the book said the answer is 67.0 L SO3