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5 5 The apparatus shown was used to measure the volume of gas evolved when a weighed mass of sodium carbonate reacted with dilute hydrochloric acid. delivery tube rubber bung syringe test tube The following procedure was used. Step 1 Solid sodium carbonate was placed in a container and weighed accurately, Step 2 The delivery tube and rubber bung were removed and the sodium carbonate was transferred to the test tube. Step 3 The container was then reweighed. Step 4 The syringe plunger was pushed in, to zero the syringe. Step 5 10.0 cm' of 0.400 moldm hydrochloric acid was then added to the sodium carbonate and the rubber bung and delivery tube rapidly replaced. Step 6 The mixture was shaken and, when the reaction had finished, the reading of the syringe was noted. Results Mass of container and sodium carbonate before transfer = 20.1359 Mass of container after transfer of the sodium carbonate = 19.8939 Mass of sodium carbonate used 0.2429 The equation for the reaction is Na CO,(s) + 2HCl(aq) → 2NaCl(aq) + CO2(g) + H2O(l)

(1) Calculate the moles of hydrochloric acid and the moles of sodium carbonate used in this experiment Use your answers to decide which reactant is in excess. Calculate the maximum volume of carbon dioxide which could be produced. Molar mass of Na.co, = 106.0 g mol Molar volume of gas = 24000 cm'mol atr.tp. (5) 5) (1) The actual volume of carbon dioxide collected was less than calculated. Give two reasons for this. 12)