(a) Define the term 'mole' as used in chemistry. (2 marks) (b) Calculate the number of moles of atoms present in 9.0 g of aluminium. [Al = 27] (2 marks) (c) Calcium carbonate decomposes on heating according to the equation: CaCO3(s) → CaO(s) + CO2(g) (i) Calculate the mass of calcium oxide produced when 50 g of calcium carbonate is completely decomposed. [Ca = 40, C = 12, O = 16] (3 marks) (ii) Calculate the volume of carbon dioxide gas produced at STP. (2 marks) (iii) How many molecules of carbon dioxide are produced in (c)(i) above? [Avogadro's number = 6.02 × 10²³] (3 marks) (d) State one industrial application of the decomposition of calcium carbonate. (1 mark)