# Calculating volume, at standard pressure and temperature - help?

5.31 x 10^24 of SO2

I'm doing an assignment through distance education and the work they tried to give me to explain the steps I don't quite understand. I don't need the answer, I need the steps! Thanks!

### 2 Answers

- ChemTeamLv 78 years agoFavorite Answer
I will take this:

"5.31 x 10^24 of SO2 "

to mean this:

5.31 x 10^24 molecules of SO2

1) determine moles of SO2

5.31 x 10^24 molecules divided by 6.022 x 10^23 molecules / mole = 8.817668 mole (I'll keep a few extra digits.)

2) determine volume:

PV = nRT

(1.00 atm) (x) = (8.817668 mol) (0.08206 L atm / mol K) (273 K)

solve for x (round to three sig figs)

Since we are at STP, we can use molar volume:

22.414 L/mol times 8.817668 mol = the desired answer

However, be aware that 22.414 works only at STP. Using PV = nRT is the general solution and works with any values of T and P.

Source(s): ChemTeam - HPVLv 78 years ago
I'm assuming that you mean 5.31 x 10^24 MOLECULES of SO2 gas.

1 mole of any substance contains 6.02 x 10^23 particles (atoms or molecules).

5.31 x 10^24 molecules SO2 x (1 mole SO2 / 6.02 x 10^23 molecules SO2) = 8.82 moles SO2

At STP (1 atm pressure and 0 degrees C), 1 mole of ANY gas has a volume of 22.4 L.

8.82 moles SO2 x (22.4 L SO2 / 1 mole SO2) = 198 L