Moles Part 3 - Volume

Aim CE5: How many moles in a liter of hydrogen?

Moles and Volume

•Even though particles of different substances have different masses

•Each particle takes up very little space individually

•Samples with the same number of particles tend to take up the same space or VOLUME

•Therefore, the volume of 1 mole of any gas at STP is always the same for any substance

•STP = standard temperature and pressure

• Standard temperature= 273 K or 0oC

• Standard pressure= 1 atmosphere or 101.3 kilopascals

• What if the pressure or temperature change? It affects the volume – but more after February break on that one!

• The volume of 1 mole of ANY gas at STP is equal to 22.4 liters

• What if you had two moles of gas?2 moles x 22.4 liters = 44.8 liters of gas

1 mole

Practice: calculate each of the following:

1. What is the volume of 1.5 moles of hydrogen gas at STP?

2. How many moles of oxygen gas are in a cylinder with 5.60 liters of oxygen?

3. What is the density of a 1.00 mole sample of gas with a mass of 50.0 grams?