BRAINCAKEElectrochemistry
Revision notes for Electrochemistry in OCR Chemistry A (H432). 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 potential of a single half cell cannot be measured on its own.
- 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.