Astatine is the element below iodine in Group 7. Bromine water is added to a solution of sodium astatide, NaAt\mathrm{NaAt}NaAt.
Which is the balanced ionic equation for the reaction that takes place?
Br2+2At−→2Br−+At2\mathrm{Br_{2}} + 2\mathrm{At^{-}} \rightarrow 2\mathrm{Br^{-}} + \mathrm{At_{2}}Br2+2At−→2Br−+At2
At2+2Br−→2At−+Br2\mathrm{At_{2}} + 2\mathrm{Br^{-}} \rightarrow 2\mathrm{At^{-}} + \mathrm{Br_{2}}At2+2Br−→2At−+Br2
Br2+2At−→2Br−+2At\mathrm{Br_{2}} + 2\mathrm{At^{-}} \rightarrow 2\mathrm{Br^{-}} + 2\mathrm{At}Br2+2At−→2Br−+2At
Br2+At−→Br−+At2\mathrm{Br_{2}} + \mathrm{At^{-}} \rightarrow \mathrm{Br^{-}} + \mathrm{At_{2}}Br2+At−→Br−+At2
230 exam-style questions on Edexcel GCSE Chemistry 1.1 Formulae, equations and hazards, covering 1.1.1 Formulae, word and balanced equations, 1.1.2 Balanced ionic equations, and 1.1.3 Hazard symbols and risk in practical work. Each one has a worked solution and a mark scheme showing where the marks go.