Give the colour and physical state of chlorine, bromine and iodine at room temperature and pressure.
The halogens are less volatile down the group. Explain this trend in volatility.
The halogens are oxidising agents. State and explain the trend in oxidising power of the halogens.
State any observations seen when concentrated sulfuric acid is added to (1) solid sodium chloride and (2) solid sodium iodide.
Give reasons for the difference between the observations in (c)(i).
When concentrated sulfuric acid is added to solid sodium bromide, NaBr, brown fumes and an acidic gas are produced, and the acidic gas decolourises acidified potassium manganate(VII) solution. This gas is a major contributor to acid rain. Write the equation for the reaction of concentrated sulfuric acid with sodium bromide.
An aqueous solution, Z, contains a mixture of sodium chloride and sodium iodide. Excess aqueous silver nitrate is added to Z in a test-tube. A yellow precipitate forms. Explain the colour of this precipitate.
Aqueous ammonia is then added to the test-tube in (d)(i), and the mass of precipitate decreases. Explain this observation.