6.1 Sodium thiosulphate, Na2S2O3(s), reacts with 200 cm3 of a hydrochloric acid solution, HCℓ(aq), of concentration 0,2 mol·dm-3 according to the following balanced equation:
Na2S2O3(s) + 2HCℓ(aq) → 2NaCℓ(aq) + S(s) + SO2(g) + H2O(ℓ)
6.1.1 Define the term concentration of a solution. (2)
6.1.2 Calculate the number of moles of HCℓ(aq) added to the sodium thiosulphate. (3)
6.1.3 Calculate the volume of SO2(g) that will be formed if the reaction takes place at STP. (3)
6.2 Menthol, the substance we can smell in mentholated cough drops, is composed of carbon (C), hydrogen (H) and oxygen (O).
During combustion of a 9,984 g sample of menthol, it is found that 28,160 g of CO2(g) and 11,520 g of H2O(g) is produced.
6.2.1 Calculate the mass of carbon (C) in the CO2. (4)
6.2.2 Use relevant calculations to determine the empirical formula of menthol. (7)
6.2.3 The molar mass of menthol is 156 g·mol-1. Determine the molecular formula of menthol. (2)
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