Half-equations and ionic equationsEdexcel A-Level Chemistry: Mind map

Exam questions on Half-equations and ionic equations

1. A student places a piece of zinc in blue copper(II) sulfate solution. After some time the blue colour fades and a brown-red solid forms on the zinc.
   Write the ionic equation for the reaction, including state symbols.2 marks
2. Acidified potassium manganate(VII) solution is used to titrate solutions containing iron(II) ions. The purple MnO₄⁻ ion is reduced to the almost colourless Mn²⁺ ion, and Fe²⁺ is oxidised to Fe³⁺.
   Write the overall ionic equation for the reaction between acidified MnO₄⁻ ions and Fe²⁺ ions.2 marks
3. A student studies two redox reactions of iron ions in aqueous solution. In the first, iron(III) ions oxidise iodide ions. In the second, acidified dichromate(VI) ions oxidise iron(II) ions.
   Write the half-equation for the reduction of Fe³⁺, the half-equation for the oxidation of I⁻ to I₂, and the overall ionic equation.3 marks