Calculating the volume at STP

Question

What is the volume of 5.00 x 10^22 molecules of carbon dioxide gas at STP?

Answer 1

At STP 1 mole of any ideal gas = 22.4 liters (this is a good value to memorize)

Convert 5.00x10²² molecules of CO₂ to moles of CO₂ using Avogadro's number:

5.00x10²² molecules x 1 mol / 6.02x10²³ molecules = 0.0831 moles CO₂

Convert moles CO₂ to liters using the 22.4 L / mol value:

0.0831 moles CO₂ x 22.4 L / mol = 18.6 L CO₂