BRAINCAKEElectrochemistry
Revision notes for Electrochemistry in Edexcel Chemistry (9CH0). Read the start of any lesson here, then sign in free for the whole lesson, the R.E.C.I.P.E. recall steps and the quiz.
- Oxidation and ReductionOxidation is the loss of electrons by an atom, ion or molecule. e.g.
- Ionic EquationsIonic half-equations show either the species that are oxidised Fe → Fe3+ + 3e- or the species that are reduced Cu2+ + 2e- → Cu They can be combined…
- Electrochemical Half CellsA half cell is made of an element in two different oxidation states.
- Electrochemical CellsAn electrochemical cell can be made by connecting two half cells together.
- The Standard Hydrogen Half CellThe standard hydrogen half cell, consists of hydrogen gas at 100kPa in contact with a platinum electrode which is dipped into an acidic solution (e.g.
- Standard Electrode Potential Eθ and the Electrochemical SeriesA copper rod dipped in a solution of copper ions generates a potential relative to the solution.
- Calomel ElectrodeA calomel electrode can be used instead of a standard hydrogen half cell as a reference electrode.
- Standard Cell Potentials Eθcell Values and Electrochemical CellsThe cell reaction is the overall chemical reaction that happens in both half cells.
- Non-Standard ConditionsThe half equations are reversible reactions.
- Cell DiagramsCell diagrams are a way of representing cells and the redox half reactions that take place in each half cell.
- Thermodynamic Feasibility of a Reaction and the Extent of a ReactionA redox reaction is thermodynamically feasible if the cell potential is positive.
- Electrochemical CellsElectrochemical cells are used as a source of electrical energy.
- Rechargeable BatteriesThe reactions in rechargeable cells can be reversed using electrical energy so the cell can be re-used.
- Alkaline Fuel CellsA fuel cell creates a voltage from the reaction of a fuel with oxygen.