A chemist is given the following:
chlorine water, bromine water and iodine solution
potassium chloride, potassium bromide and potassium iodide solutions
a spotting tile and dropping pipettes
Devise an experiment to determine the order of reactivity of chlorine, bromine and iodine. Your answer should include the expected results and how they are used to decide the order.
Astatine is below iodine in group 7. It forms astatide ions, At−\mathrm{At^{-}}At−.
Predict what would be seen when chlorine water is added to a solution of potassium astatide.
Write the ionic equation for the reaction between chlorine and astatide ions.
A bottle of chlorine water contains 3.55 g of chlorine, Cl2\mathrm{Cl_{2}}Cl2, in each dm3\mathrm{dm^{3}}dm3. Cl2(aq)+2KBr(aq)→2KCl(aq)+Br2(aq)\mathrm{Cl_{2}(aq)} + \mathrm{2KBr(aq)} \rightarrow \mathrm{2KCl(aq)} + \mathrm{Br_{2}(aq)}Cl2(aq)+2KBr(aq)→2KCl(aq)+Br2(aq)
Calculate the minimum volume of this chlorine water, in cm3\mathrm{cm^{3}}cm3, needed to react with all the potassium bromide in 25.0 cm3\mathrm{cm^{3}}cm3 of 0.100 mol dm−3\mathrm{mol\,dm^{-3}}moldm−3 potassium bromide solution.
Relative atomic mass: Cl = 35.5
41 exam-style questions on Edexcel GCSE Chemistry 7.2 Group 7, covering 7.2.1 Physical properties of the halogens, 7.2.2 Reactions of the halogens, 7.2.3 Relative reactivity and displacement reactions of the halogens, and 7.2.4 Halogen displacement as a redox reaction. Each one has a worked solution and a mark scheme showing where the marks go.