Why do Cathodes carry a positive charge and Anodes carry a negative charge in galvanic cells, but in electrolytic cells, Cathodes have a negative charge and Anodes have a positive charge? I’m a grade 12 chemistry student and I’m having trouble understanding this concept. Could someone please explain the rationale behind this apparent reversal of charges in the two types of cells?
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In galvanic cells, such as batteries, the cathode is the positive terminal, and the anode is the negative terminal. This is because galvanic cells generate electricity through a spontaneous chemical reaction. During this reaction, electrons flow from the anode (negative terminal) to the cathode (positive terminal), creating an electric current.
On the other hand, in electrolytic cells, an external source of electrical energy is used to drive a non-spontaneous chemical reaction. The cathode in an electrolytic cell is connected to the negative terminal of the power supply, and the anode is connected to the positive terminal. The external electrical energy forces the non-spontaneous reaction to occur, and as a result, electrons flow from the power supply to the cathode (negative terminal) and from the anode (positive terminal) back to the power supply.
So, the polarity of the electrodes in galvanic and electrolytic cells is determined by the direction of electron flow. In galvanic cells, the cathode is positive because electrons flow from the anode to the cathode. In electrolytic cells, the cathode is negative because electrons flow from the power supply to the cathode.
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