15 Electrochemistry - Summary.pdf

Electrochemistry The electrochemical series is a table An electrode is a conductor connected to showing metals arranged in order of the positive or negative end of a battery. tendency to lose electrons. 1. Inert Electrodes: These do not react A metal will displace another metal below it with the ele...

Electrochemistry The electrochemical series is a table An electrode is a conductor connected to showing metals arranged in order of the positive or negative end of a battery. tendency to lose electrons. 1. Inert Electrodes: These do not react A metal will displace another metal below it with the electrolyte (eg. Graphite & in the electrochemical series from a solution platinum) of its salt 2. Active Electrodes: These react with Displacement Experiments the electrolyte - An active anode 1. Zinc granules dipped into acidified electrode gradually dissolves as copper sulfate solution 2. Magnesium ribbon dipped in acidified copper sulfate solution Electrolysis is the breaking up of a electricity is passed through the electrolyte (eg. Copper). Experiment: Copper dichromate green colour in solution (CuCr₂O₇ solution) substance due to an electric current When electrolysis is carried out, the passing through it in aqueous solution or solution breaks up into when molten. An electrolyte is a substances that conducts electricity when dissolved in water or when molten. The Cu²⁺ cations are attracted to the cathode (blue colour appears) The CuCr₂O₇²⁻ anions are attracted to the anode (yellow colour appears) Oxidation occurs at the anode, reduction occurs at the cathode Memory Aid : CatNAP - Cathode Negative Anode Positive Electrolysis of Aqueous Sodium Sulfate using Universal Indicator – Anode - H ions are acidic & cause the indicator to turn red. Cathode - These OH⁻ ions are basic & cause the indicator to turn blue Electrolysis of Acidified Water - Hoffman Voltameter. Anode - O₂ gathers at the anode Cathode - H₂ gathers at the cathode. Twice as much H₂ is observed when compared to O₂ Electroplating - This involves coating one inexpensive metal with another more expensive metal. Nickel on silver.