Core Practical – Investigating Chemical Reactions

Question 1

1) What is the change in mass when copper carbonate is heated?
2) What does copper carbonate form when it is heated?
3) What is thermal decomposition?

Answer 1

1) The loss in mass is due to the loss of carbon dioxide gas, this is thermal decomposition.
2) It breaks down to produce copper oxide and carbon dioxide which is released
3) Thermal decomposition is a chemical reaction that happens when a compound breaks down when heated, it is an endothermic reaction because it absorbs heat energy.

Question 2

1) What happens to the mass of magnesium when heated?
2) What is the reaction called when magnesium is heated?

Answer 2

1) The increase in mass is due to the fact that oxygen from the air has combined with the magnesium to make magnesium oxide, MgO.
2) When magnesium is heated it is called oxidation because the oxygen is combining with the metal.