1. Do now! Can you finish the questions we started last lesson? (Page 83) Mole test Wednesday 4 th November

2. Last lesson - Working out the formula

3. Working out the formula 1.4 g of Nitrogen reacts with 0.3 g of hydrogen to form a compound. What is the formula of the compound?

4. Working out the formula 1.4 g of Nitrogen reacts with 0.3 g of hydrogen to form a compound. What is the formula of the compound? First work out the number of moles 1.4g Nitrogen = mass/RAM = 1.4/14 = 0.1 0.3g hydrogen = mass/RAM = 0.3/1 = 0.3

5. Working out the formula 1.4 g of Nitrogen reacts with 0.3 g of hydrogen to form a compound. What is the formula of the compound? Work out the ratio of the number of moles of each element to the lowest whole numbersN:H 0.1:0.3 1:3

6. Working out the formula 1.4 g of Nitrogen reacts with 0.3 g of hydrogen to form a compound. What is the formula of the compound? Therefore there are 3 times as many hydrogen atoms as N atoms in the compound. The formula must be NH 3 (ammonia)

7. Today’s lesson Using mole calculations in a “real” example

8. Let’s do an experiment!

9. Can you gather around Mr Porter?

10. Formula of magnesium oxide? Mass of magnesium Moles of magnesium (1 mole = 24 g) Mass of crucible and magnesium Mass of magnesium oxide and crucible Mass of oxygen that reacted with magnesium Number of moles of oxygen (1 mole = 16g) Formula of oxide