Electrochemistry

Reinforce Oxidation/Reduction

Always show the corresponding reduction process when discussing oxidation and vice versa. Ask students to think about where electrons are moving to or from.

Write Half Equations for Organic Reactions

You rarely see organic reactions split up into two half equations. You could show the link between redox and organic chemistry by getting them to write the half equations for reactions like the oxidation of an aldehyde, ketone or alcohol with permanganate, for example. You want them to realise that it goes from purple to colourless then they have to write it out. 

Link to YouTube Video: Ethanol + Permangenate Oxidation

Demonstrate Reaction During Lecture

Demonstrate a reaction that occurs within the time frame of your lecture. Start it at the beginning of the lecture, and then go back to it in the middle and at the end to show what has happened. For example, you can use copper in silver nitrate solution. 

Link to YouTube Video: Silver Production from Silver Nitrate

Everyday Examples - Bike Rust

Use everyday examples. A great question to have at the end of your lecture would be ‘What is reduced when my bike rusts?’ They might understand that their bike rusts, but what is reduced? Oxygen and water are reduced. But we don’t see the reduction, we just see the iron changing. You have done your job well if someone asks the question ‘What is reduced when my bike is oxidised?’

Physical Representations

Use little cartoons or even just physical representations. Have a jar of marbles representing electrons and move them around. Because sometimes having physical things to manipulate helps with understanding of a concept. Even though in reality it’s nothing like it, it’s just a representation.

Zinc in Copper Sulphate Demonstration

Put zinc metal in copper sulphate solution and record it with the visualiser. Have it running as you talk about the push and pull of electrons. Then bring it up and say, ‘look what’s happened here, the zinc has rusted’. Students make more of a link when they see things being visualised. The oxidation of metal has a very visual impact on them. But then, they might forget about the reduction side, so you need to remind them of it.

Link to YouTube Video: Copper Sulfate + Zinc

Copper in Silver Nitrate Demonstration

If you put copper metal in a silver nitrate solution, the solution becomes blue and you get silver metal. Ag+ is becoming Ag and Cu is becoming Cu++. The students see both oxidation and reduction happening - and happening at the same time. If you do it close to Christmas you can use the copper filament to make a Christmas tree, and then you get a nice silver on the Christmas tree. They know that it was a colourless ion solution, but then they can see silver on the Christmas tree. So they can easily see the reduction.

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