1. Coke in the blast furnace
= carbon atom
= oxygen atom + C O2
CO2 + +
C + CO2  2CO

2. Thermal decomposition of calcium carbonate.
= carbon atom
= calcium atom
= oxygen atom +
CaCO3  CaO + CO2

3. Adding water to calcium oxide
= oxygen atom
= hydrogen atom
= calcium atom +
CaO + H2O  Ca(OH)2

4. Adding carbon dioxide to calcium hydroxide
= oxygen atom
= hydrogen atom
= carbon atom
= calcium atom + +
CaCO3

5. Reduction of iron oxide
= carbon atom
= iron atom
= oxygen atom + +
Fe2O3 + 3CO  2 Fe + 3CO2

6. Reduction of iron oxide
= carbon atom
= iron atom
= oxygen atom + +
2Fe2O3 + 3C  4Fe + 3CO2

7. Combustion CH4 + 2O2  CO2 + 2H2O = carbon atom = hydrogen atom
= oxygen atom + +
CH4 + 2O2  CO2 + 2H2O

8. Acid and metal 2HCl + 2Na  2NaCl + H2 = Sodium atom = hydrogen atom
= chlorine atom + +
2HCl + 2Na  2NaCl + H2

9. Acid and alkali HCl + NaOH  NaCl + H2O = Sodium atom = hydrogen atom
= chlorine atom
= Sodium atom
= hydrogen atom
= oxygen atom + +
HCl + NaOH  NaCl + H2O

10. Decomposition of sodium carbonate
= carbon atom
= Sodium atom
= oxygen atom +
Na2CO3  CO2 + Na2O

11. Acid and carbonate Na2CO3 + HCl  2NaCl + CO2 + H2O = carbon atom
= hydrogen atom
= oxygen atom
= Sodium atom
= chlorine atom + + +
Na2CO3 + HCl  2NaCl + CO2 + H2O

12. Acid and alkali HCl + NaOH  ? + H2O NaCl = Sodium atom
= chlorine atom
= oxygen atom
= hydrogen atom + +
HCl + NaOH  ? H2O
NaCl

13. C + O2  CO2 Working out masses 24/12 = 2 moles
If I have 24g of carbon, what mass of carbon dioxide will I produce?
C + O2  CO2
Look at the ratio of carbon to carbon dioxide (look at the big numbers only).
2 x 44 = 88g of CO2
1:1 ratio
Calculate the number of moles of carbon using moles = mass/Ar
Calculate the mass of CO2 using mass = moles x Mr
There is a 1:1 ratio, so there are 2 moles of CO2.
24/12 = 2 moles
Use the ratio to work out the number of moles of CO2.

14. Use the equation to calculate thee mass iron we can make if we start with 160g of Fe2O3.
Fe2O3 + 3CO  2 Fe + 3CO2
2) If we start with 8g of methane, what is the mass of carbon dioxide we can produce?
CH4 + 2O2  CO2 + 2H2O
3) If we have 92g of sodium, what mass of sodium chloride will we produce?
2HCl + 2Na  2NaCl + H2
If we made 112g of iron, what mass of iron oxide did we start with?
2Fe2O3 + 3C  4Fe + 3CO2

15. Answers
112g of iron.
22g of CO2.
234g of NaCl.
160g of Fe2O3.

16. Coke in the blast furnace
= carbon atom
= oxygen atom + C O2
CO2 + +

17. Thermal decomposition of calcium carbonate.
= carbon atom
= calcium atom
= oxygen atom +

18. Adding water to calcium oxide
= oxygen atom
= hydrogen atom
= calcium atom +

19. Adding carbon dioxide to calcium hydroxide
= oxygen atom
= hydrogen atom
= carbon atom
= calcium atom + +
CaCO3

20. Reduction of iron oxide
= carbon atom
= iron atom
= oxygen atom + +
Fe2O3 + 3CO  2 Fe + 3CO2

21. Reduction of iron oxide
= carbon atom
= iron atom
= oxygen atom + +
2Fe2O3 + 3C  4Fe + 3CO2

22. Combustion
= carbon atom
= hydrogen atom
= oxygen atom + +

23. Acid and metal
= Sodium atom
= hydrogen atom
= chlorine atom + +

24. ? Acid and alkali NaCl HCl + NaOH  ________ + H2O = Sodium atom
= hydrogen atom
= chlorine atom
= Sodium atom
= oxygen atom ? + +
NaCl
HCl + NaOH  ________ + H2O

25. Adding carbon dioxide to calcium hydroxide
= oxygen atom
= hydrogen atom
= calcium atom
= sulphur atom ? + +
CaSO4
CaO + H2SO4  ________ + H2O

26. ? Combustion H2O + CO2  _________ H2CO3 = carbon atom = hydrogen atom
= oxygen atom ? +
H2CO3
H2O + CO2  _________

27. Combustion
= carbon atom
= oxygen atom ? + O2
C + _____  CO2

28. Thermal decomposition of calcium carbonate.
= carbon atom
= calcium atom
= oxygen atom ? + ?
CaCO3  CaO + CO2

29. Adding water to calcium oxide.
= carbon atom
= calcium atom
= oxygen atom
= hydrogen atom ? + ?
CaO + H2O  Ca(OH)2

30. Adding water to calcium oxide.
= carbon atom
= calcium atom
= oxygen atom
= hydrogen atom ? + + ?
Ca(OH)2 + CO2  CaCO3 + H2O

31. Decomposition of sodium carbonate
= carbon atom
= Sodium atom
= oxygen atom +

32. Acid and carbonate = carbon atom = hydrogen atom = oxygen atom
= Sodium atom
= chlorine atom + + +