1. Particles and Moles
Substances can be measured in several ways. They can be:
Number of grams
Number of particles
Number of moles
One mole of atoms is equal to the AVOGADRO number of particles (6.02X1023)
The mass of one mole of atoms is equal to the Relative Atomic Mass (top number on periodic table).

2. Task Answer the following
What is the formula mass of Carbon?
What is the mass of 1 mole of C atoms?
What is the formula mass of carbon dioxide CO2?
What is the mass of 1 mole of carbon dioxide?

3. Particles and Moles
Calculating number of moles

4. Example What is the mass (g) of 3.5 moles of Magnesium (Mg)?
Mass (g) = Mr x No. of moles
Mass (g) = 24 x 3.5 = 84g

5. Now try these
Mass (g) = Mr x No. of moles
1.What is the mass (g) of 2.6 moles of Iron? 2. What is the mass (g) of 5.5 moles of gold? 3. What is the mass (g) of 1.8 moles of calcium? 4. What is the mass of 6.2 moles of oxygen gas? 5. What is the mass of 2.9 moles of carbon dioxide?
145.6g
1083.5g
72.0g
198.4g
127.6g

6. Example How many moles are there in 66g of carbon dioxide?
Mass of CO2 = 66g Mr CO2 = 44
No. of moles = Mass in g Mr
Mass (g) = 66 = 1.5 moles 44

7. Now try these No. of moles = Mass in g Mr
1.How many moles are there in 26g of iron? 2. How many moles are there in 55g of gold? 3. How many moles are there in 18g of calcium? 4. How many moles are there in 62g of oxygen gas? 5. How many moles are there in 29g of carbon dioxide?
0.46 moles
0.279 moles
0.45 moles
moles
No. of moles = Mass in g Mr
0.659 moles