1. THE MOLE CONTENTS What is a mole and why do we use it? Calculating the number of moles of a single substance Reacting mass calculations

2. Before you start it would be helpful to… know how to balance simple equations know how to re-arrange mathematical formulae THE MOLE DON’T BE LEFT IN THE DARK!

3. WHAT IS A MOLE ? it is the standard unit of amount of a substance - it is just a number, a very big number it is a way of saying a number in words, just like... DOZEN for 12 SCORE for 20 GROSS for 144 THE MOLE

4. HOW BIG IS IT ? 602200000000000000000000 (Approximately)... THAT’S BIG !!! It is a lot easier to write it as... 6.022 x 10 23 THE MOLE WHAT IS A MOLE ? it is the standard unit of amount of a substance - it is just a number, a very big number it is a way of saying a number in words, just like... DOZEN for 12 SCORE for 20 GROSS for 144

5. HOW BIG IS IT ? 602200000000000000000000 (Approximately)... THAT’S BIG !!! It is a lot easier to write it as... 6.022 x 10 23 It is also known as... AVOGADRO’S NUMBER It doesn’t matter what the number is as long as everybody sticks to the same value ! THE MOLE WHAT IS A MOLE ? it is the standard unit of amount of a substance - it is just a number, a very big number it is a way of saying a number in words, just like... DOZEN for 12 SCORE for 20 GROSS for 144

6. WHY USE IT ? Atoms and molecules don’t weigh much so it is easier to count large numbers of them. In fact it is easier to weigh substances. Using moles tells you... how many particles you get in a certain mass the mass of a certain number of particles DO I NEED TO KNOW ANYTHING ELSE ? Yes, it would help if you can balance equations ANDKeep trying, you will get the idea... EVENTUALLY! THE MOLE

7. WHAT IS IT?The standard unit of amount of a substance - just as the standard unit of length is a METRE It is just a number, a very big number It is also a way of saying a number in words like DOZENfor 12 GROSSfor 144 THE MOLE – AN OVERVIEW

8. WHAT IS IT?The standard unit of amount of a substance - just as the standard unit of length is a METRE It is just a number, a very big number It is also a way of saying a number in words like DOZENfor 12 GROSSfor 144 HOW BIG IS IT ?602200000000000000000000 (approx) - THAT’S BIG !!! It is a lot easier to write it as 6.022 x 10 23 And anyway it doesn’t matter what the number is as long as everybody sticks to the same value ! THE MOLE – AN OVERVIEW

9. WHAT IS IT?The standard unit of amount of a substance - just as the standard unit of length is a METRE It is just a number, a very big number It is also a way of saying a number in words like DOZENfor 12 GROSSfor 144 HOW BIG IS IT ?602200000000000000000000 (approx) - THAT’S BIG !!! It is a lot easier to write it as 6.022 x 10 23 And anyway it doesn’t matter what the number is as long as everybody sticks to the same value ! WHY USE IT ?Atoms and molecules don’t weigh much so it is easier to count large numbers of them. In fact it is easier to weigh substances. Using moles tells you :-how many particles you get in a certain mass the mass of a certain number of particles THE MOLE – AN OVERVIEW

10. CALCULATING THE NUMBER OF MOLES OF A SINGLE SUBSTANCE moles= mass / molar mass mass= moles x molar mass molar mass= mass / moles UNITS mass g or kg molar mass g mol -1 orkg mol -1 THE MOLE MOLES = MASS MOLAR MASS MOLES = MASS MOLAR MASS MASS MOLES x MOLAR MASS COVER UP THE VALUE YOU WANT AND THE METHOD OF CALCULATION IS REVEALED

11. 1. Calculate the number of moles of oxygen molecules in 4g MOLES OF A SINGLE SUBSTANCE

12. 1. Calculate the number of moles of oxygen molecules in 4g oxygen molecules have the formula O 2 relative mass will be 2 x 16 = 32 ; molar mass will be 32g mol -1 MOLES OF A SINGLE SUBSTANCE

13. 1. Calculate the number of moles of oxygen molecules in 4g oxygen molecules have the formula O 2 relative mass will be 2 x 16 = 32 ; molar mass will be 32g mol -1 moles = mass = 4g= 0.125 mol molar mass 32g mol -1 MOLES OF A SINGLE SUBSTANCE

14. 1. Calculate the number of moles of oxygen molecules in 4g oxygen molecules have the formula O 2 relative mass will be 2 x 16 = 32 ; molar mass will be 32g mol -1 moles = mass = 4g= 0.125 mol molar mass 32g mol -1 MOLES OF A SINGLE SUBSTANCE

15. 1. Calculate the number of moles of oxygen molecules in 4g oxygen molecules have the formula O 2 relative mass will be 2 x 16 = 32 ; molar mass will be 32g mol -1 moles = mass = 4g= 0.125 mol molar mass 32g mol -1 2.What is the mass of 0.25 mol of Na 2 CO 3 ? MOLES OF A SINGLE SUBSTANCE

16. 1. Calculate the number of moles of oxygen molecules in 4g oxygen molecules have the formula O 2 relative mass will be 2 x 16 = 32 ; molar mass will be 32g mol -1 moles = mass = 4g= 0.125 mol molar mass 32g mol -1 2.What is the mass of 0.25 mol of Na 2 CO 3 ? Relative Molecular Mass of Na 2 CO 3 = (2x23) + 12 + (3x16) = 106 Molar mass of Na 2 CO 3 = 106g mol -1 MOLES OF A SINGLE SUBSTANCE

17. 1. Calculate the number of moles of oxygen molecules in 4g oxygen molecules have the formula O 2 relative mass will be 2 x 16 = 32 ; molar mass will be 32g mol -1 moles = mass = 4g= 0.125 mol molar mass 32g mol -1 2.What is the mass of 0.25 mol of Na 2 CO 3 ? Relative Molecular Mass of Na 2 CO 3 = (2x23) + 12 + (3x16) = 106 Molar mass of Na 2 CO 3 = 106g mol -1 mass = moles x molar mass = 0.25 x 106 = 26.5g MOLES OF A SINGLE SUBSTANCE

18. 1. Calculate the number of moles of oxygen molecules in 4g oxygen molecules have the formula O 2 relative mass will be 2 x 16 = 32 ; molar mass will be 32g mol -1 moles = mass = 4g= 0.125 mol molar mass 32g mol -1 2.What is the mass of 0.25 mol of Na 2 CO 3 ? Relative Molecular Mass of Na 2 CO 3 = (2x23) + 12 + (3x16) = 106 Molar mass of Na 2 CO 3 = 106g mol -1 mass = moles x molar mass = 0.25 x 106 = 26.5g MOLES OF A SINGLE SUBSTANCE