CIE Jun 2017 v3 Paper 2 Q2

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The halogens, chlorine, bromine and iodine, and their compounds, show a variety of similarities and trends in their physical and chemical properties. (a) (i) Give the colours and states of chlorine, bromine and iodine at room temperature and pressure. PMT colour state halogen chlorine bromine iodine [2] (ii) The halogens become less volatile down the group. Explain this trend in volatility.[2] (b) The halogens are oxidising agents. State and explain the trend in oxidising power of the halogens.[3] (c) Concentrated sulfuric acid reacts with solid sodium halides. (i) State any observations that would be made on addition of concentrated sulfuric acid to solid sodium chloride,solid sodium iodide.[2]UCLES 2017 9701/23/M/J/17<br /> PMT (ii) Give reasons for the difference in the observations in (i).[2] (iii) The addition of concentrated sulfuric acid to solid sodium bromide, NaBr, produces brown fumes and an acidic gas that decolourises acidified potassium manganate(VII) solution. This acidic gas is a significant contributor to acid rain. Write the equation for the reaction of concentrated sulfuric acid with sodium bromide.[2] (d) An aqueous solution, Z, contains a mixture of sodium chloride and sodium iodide. (i) Excess aqueous silver nitrate is added to Z in a test-tube. A yellow precipitate forms. Explain the colour of this precipitate.[1] (ii) Aqueous ammonia is then added to the test-tube in (i). The mass of precipitate decreases. Explain this observation.[1] [Total: 15]UCLES 2017 9701/23/M/J/17 [Turn over<br />

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