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Oxidation & Reduction (Galvanic cell) (1 Viewer)

nml10

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In a previous HSC question about Galvanic Cells, a question asked

What happens when you remove the voltmeter from the circuit and replace it with an electrical generator? The generator causes the electrod to increase in mass. Explain, using an equation, why the copper electrode will increase in mass.

Is this relevant to the syllabus dot points?
D:
 
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The electrical generator will generate current (obviously), current is a net flow of electrons, electrons will flow into the electrode and into the ionic solution, copper ions in solution will accept these electrons and be reduced, the reduced ions will precipitate into solid copper and deposit on the copper electrode, this results in an increase in mass of the electrode.
 

Drongoski

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For one not doing chemistry, that's not bad at all.
 
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hp-gg

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I know this thread is almost 6 months old but for anyone else who was wondering and led here by Google: the generator causes a non-spontaneous reaction to occur. What happens is that the regular red/ox reaction is reversed. So in this case, the copper was initially being oxidised and reducing the ion in the other solution, when there was no 'work' from an external source involved -i.e. there was just a voltmeter. Now the total opposite occurs, since there is 'work' being input from the powerpack, so the Cu2+(aq) in solution where the copper electrode is, is being reduced into Cu(s).This causes mass increase since solid copper is deposited on the electrode, as said by ohexploitable. For more detail, search 'electrolytic cell'.
 

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