GCSE›Edexcel GCSE Chemistry›Mind mapsElectrolytic ProcessesEdexcel GCSE Chemistry: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsThe basicsElectrolyte: ionic compound molten or dissolvedd.c. supply decomposes the electrolyteCations go to the negative cathodeAnions go to the positive anodeMolten compoundsMetal forms at the cathodeNon-metal forms at the anodeMolten lead bromide gives lead and bromineAqueous solutionsCathode: hydrogen unless metal less reactiveAnode: oxygen unless a halide is presentCopper chloride gives Cu and ClX2\ce{Cl2}ClX2Sodium chloride gives HX2\ce{H2}HX2 and ClX2\ce{Cl2}ClX2Electrolysissplitting with currente-CuCl2Half equationsCathode is reduction: CuX2++2 eX−→Cu\ce{Cu^2+ + 2e- -> Cu}CuX2++2eX−CuAnode is oxidation: 2 ClX−→ClX2+2 eX−\ce{2Cl- -> Cl2 + 2e-}2ClX−ClX2+2eX−OIL RIG: oxidation is loss, reduction is gainPurifying copperImpure copper anode dissolvesPure copper deposits on the cathodeInsoluble impurities fall as anode sludgeAnode: Cu→CuX2++2 eX−\ce{Cu -> Cu^2+ + 2e-}CuCuX2++2eX−Exam tipsDo not mix up cathode and anodeUse OIL RIG for the electrodes