Calcium carbonate breaks down on heating to produce calcium oxide and carbon dioxide gas. CaCO3 ® CaO + CO2

A student heats 15 g of calcium carbonate strongly in a crucible.

Relative atomic masses (Ar): Ca = 40, C = 12, O = 16.

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a Calculate the number of moles in 15 g of calcium carbonate. (2 marks)

b Use your answer to part a to determine the number of moles of calcium oxide that will be produced. (1 mark)

c Calculate the mass of calcium oxide produced by this reaction. (2 marks)

4 A student is preparing a sample of sodium nitrate, NaNO3.

She mixes 17 g of sodium oxide with an excess of nitric acid. The equation for the reaction is:

Na2O + 2HNO3 ® 2NaNO3 + H2O

Relative atomic masses (Ar): Na = 23, O = 16, N = 14, H = 1.

a Calculate the number of moles in 17 g of sodium oxide. (2 marks)

b Calculate the maximum mass of sodium nitrate that can be produced in this reaction. (3 marks)

5 Aluminium and iron oxide (Fe2O3) react together to produce aluminium oxide (Al2O3). The equation for the reaction is:

2Al + Fe2O3 ® Al2O3 + 2Fe

Calculate the mass of iron that is produced by reacting 20 g of iron oxide with an excess of aluminium.

Relative atomic masses (Ar): Al = 27, O = 16, Fe = 56. (4 marks)