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October 29, 2025, 03:36:56 pm

Author Topic: Anode/Cathode in Electrolysis  (Read 2013 times)  Share 

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Chazef

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Anode/Cathode in Electrolysis
« on: June 29, 2013, 11:38:41 pm »
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Hey I'm struggling to understand how an anode can be positive during electrolysis. I don't think I've been so stumped by something so seemingly simply in all of chemistry so far. From what I understand, the anode is where oxidation occurs, where electrons leave and what is connected to the positive terminal of the galvanometer/power supply. If you turn a galvanic cell into an electrolytic cell, aren't you just turning the anode into a cathode and the cathode into an anode, meaning that the anode is still negative and the cathode is still positive? WHYYYYYYYYYYYYYYYYYYYYYYYYYYY
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Re: Anode/Cathode in Electrolysis
« Reply #1 on: July 01, 2013, 11:44:46 am »
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The process is the opposite though. In a galvanic cell, chemical energy is converted into electrical energy. In an electrolytic cell, electrical energy is converted into chemical energy. I'm not exactly sure "how" this affects the change in terminals but it looking at it from a logical perspective, it must have something to do with the process of the function in each cell.

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Re: Anode/Cathode in Electrolysis
« Reply #2 on: July 01, 2013, 12:34:24 pm »
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You're right, the anode is where oxidation occurs, that is where the electrons are lost/where the electrons come from.
The main difference is in a galvanic cell, the reaction is spontaneous so electrons happily go from negative where they're produced, to positive where they're consumed.
In an electrolytic cell, you're pumping electrons the other way and forcing them to go from positive to negative. Because the cathode is always where reduction occurs, the electrons go to the cathode and hence the cathode is now negative. The anode, which is losing electrons is positive.