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प्रश्न
Why is anode in galvanic cell considered to be negative and cathode positive electrode?
उत्तर
A galvanic cell works basically in reverse to an electrolytic cell. The anode is the electrode where oxidation takes place, in a galvanic cell, it is the negative electrode, as when oxidation occurs, electrons are left behind on the electrode.
The anode is also the electrode where metal atoms give up their electrons to the metal and go into solution. The electron left behind on it renders it effectively negative and the electron flow goes from it through the wire to the cathode.
Positive aqueous ions in the solution are reduced by the incoming electrons on the cathode. This is why the cathode is a positive electrode because positive ions are reduced to metal atoms there.
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संबंधित प्रश्न
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Use the data given in below find out which option the order of reducing power is correct.
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Read the passage given below and answer the questions that follow:
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Oxidation-reduction reactions are commonly known as redox reactions. They involve transfer of electrons from one species to another. In a spontaneous reaction, energy is released which can be used to do useful work. The reaction is split into two half-reactions. Two different containers are used and a wire is used to drive the electrons from one side to the other and a Voltaic/Galvanic cell is created. It is an electrochemical cell that uses spontaneous redox reactions to generate electricity. A salt bridge also connects to the half-cells. The reading of the voltmeter gives the cell voltage or cell potential or electromotive force. If \[\ce{E^0_{cell}}\] is positive the reaction is spontaneous and if it is negative the reaction is non-spontaneous and is referred to as electrolytic cell. Electrolysis refers to the decomposition of a substance by an electric current. One mole of electric charge when passed through a cell will discharge half a mole of a divalent metal ion such as Cu2+. This was first formulated by Faraday in the form of laws of electrolysis.
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OR
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Given:
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