1. Chemical Calculations for Year X

3. n 22.4 m n M num n 6x10 23

4. You need to become familiar with the following types of calculations 1. mole > mole 2. mole > gas volumes (STP + NTP) 3 mole > mass 4 mass > mole 5 mass > mass easiest hardest, most steps

5. Some hand written examples 1. mole > mole

6. Some hand written examples 1. mole > mole

7. Some hand written examples 2. mole > gas volumes (STP + NTP) Hydrogen gas is produced when magnesium is added to dilute hydrochloric acid. Mg + 2HCl ---------à MgCl 2 + H 2 Wh at volume of gas is produced when 0.6 moles of the acid is used completely?

8. Mg + 2HCl ---------à MgCl 2 + H 2 Hydrogen gas is produced when magnesium is added to dilute hydrochloric acid. Mg + 2HCl ---------à MgCl 2 + H 2 Wh at volume of gas is produced when 0.6 moles of the acid is used completely?

9. Some hand written examples 2. mole > gas volumes (STP + NTP) The lab prep for oxygen requires hydrogen peroxide and the catalyst manganese dioxide 2H 2 O 2 ------------à 2H 2 O + O 2 25 mL of oxygen gas is produced during an experiment. How many moles of hydrogen peroxide has decomposed?

10. The lab prep for oxygen requires hydrogen peroxide and the catalyst manganese dioxide 2H 2 O 2 ------------à 2H 2 O + O 2 25 mL of oxygen gas is produced during an experiment. How many moles of hydrogen peroxide has decomposed? 2H 2 O 2 ------------à 2H 2 O + O 2

11. Some hand written examples 2. mole > gas volumes (STP + NTP) Carbon dioxide is made by adding hydrochloric acid to calcium carbonate. A teacher requires 150mL at NTP. How g of calcium carbonate should he use? CaCO 3 + 2HCl --------à CaCl 2 + H 2 O + CO 2

12. Carbon dioxide is made by adding hydrochloric acid to calcium carbonate. A teacher requires 150mL at NTP. How g of calcium carbonate should he use? CaCO 3 + 2HCl --------à CaCl 2 + H 2 O + CO 2

13. Q1 Hydrogen sulphide H 2 S gas can be made by adding sulphuric acid to iron sulphide. (FeS) Iron sulphate is also produced during this reaction. If 4 moles of iron sulphide is used what volume of gas will be produced at STP? Q2 A technician requires 500mL of laughing gas (N 2 O). How many moles of ammonium nitrate should be decomposed to produce this? NH 4 NO 3 --------à N 2 O + 2H 2 O Q3 500Kg of old car panels need to be dissolved in sulphuric acid. Assuming that the car panels are steel (mainly iron) How many moles of sulphuric acid is required for this job? Fe + H 2 SO 4 --------à FeSO 4 + H 2 Q4 Copper metal can be extracted from copper oxide CuO by simply heating it with carbon powder C. If 750g of copper is required, how many g of copper oxide should be treated with carbon. What volume of carbon dioxide will be produced during this process? (NTP conditions) Questions

15. Some hand written examples 2. mole > gas volumes (STP + NTP)

16. Some hand written examples 3 mole > mass

17. Some hand written examples 3 mole > mass