Distinguish between Electrolytic cell and Voltaic Cell

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Doubtly · Accepted Answer

Answer: An electrolytic cell uses electrical energy to bring about a non-spontaneous chemical reaction, whereas a voltaic (galvanic) cell produces electrical energy from a spontaneous redox reaction. Other differences are tabulated below. PointElectrolytic cellVoltaic (galvanic) cell Energy conversionElectrical energy is converted into chemical energy.Chemical energy is converted into electrical energy. Nature of reactionNon-spontaneous redox reaction ( Δ G>0 ), forced by an external source.Spontaneous redox reaction ( Δ G<0 ). External sourceNeeds an external d.c. source (battery) to work; it consumes electrical energy.No external source needed; it supplies electrical energy to an external circuit. Polarity of electrodesAnode is positive, cathode is negative.Anode is negative, cathode is positive. ConstructionUsually both electrodes dip in the same electrolyte in a single vessel; no salt bridge.Usually two half-cells, each having a metal (e.g. Zn, Cu) in its own salt solution, joined by a salt bridge. ElectrodesMay be inert (Pt, graphite) or active, the same or different.Generally two different electrodes with different electrode potentials. Reaction at electrodesOxidation at anode, reduction at cathode (same as galvanic), but driven by the applied voltage.Oxidation at anode, reduction at cathode, occurring on their own. Examples / usesElectrolysis of water or molten NaCl, electroplating, electrorefining.Daniell cell, dry cell, lead-acid battery during discharge, fuel cells.

Doubtly AI · Answer

Answer: A voltaic (galvanic) cell converts chemical energy into electrical energy by a spontaneous redox reaction, while an electrolytic cell uses electrical energy to drive a non-spontaneous reaction. PointElectrolytic cellVoltaic (galvanic) cell Energy changeElectrical energy → chemical energyChemical energy → electrical energy ReactionNon-spontaneous ( Δ G > 0 ), forced by an external sourceSpontaneous ( Δ G < 0 ) External sourceNeeds a battery / DC supplyNot needed; the cell itself is the source of emf AnodePositive electrode (oxidation)Negative electrode (oxidation) CathodeNegative electrode (reduction)Positive electrode (reduction) ConstructionUsually both electrodes in one vessel with one electrolyteUsually two half-cells joined by a salt bridge ExamplesElectrolysis of water or fused NaCl, electroplating, electrorefiningDaniell cell, dry cell, lead storage battery (discharging) In both cells oxidation occurs at the anode and reduction at the cathode; only the signs of the electrodes differ.

Distinguish between Electrolytic cell and Voltaic Cell

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Point	Electrolytic cell	Voltaic (galvanic) cell
Energy conversion	Electrical energy is converted into chemical energy.	Chemical energy is converted into electrical energy.
Nature of reaction	Non-spontaneous redox reaction (\(\Delta G>0\)), forced by an external source.	Spontaneous redox reaction (\(\Delta G<0\)).
External source	Needs an external d.c. source (battery) to work; it consumes electrical energy.	No external source needed; it supplies electrical energy to an external circuit.
Polarity of electrodes	Anode is positive, cathode is negative.	Anode is negative, cathode is positive.
Construction	Usually both electrodes dip in the same electrolyte in a single vessel; no salt bridge.	Usually two half-cells, each having a metal (e.g. Zn, Cu) in its own salt solution, joined by a salt bridge.
Electrodes	May be inert (Pt, graphite) or active, the same or different.	Generally two different electrodes with different electrode potentials.
Reaction at electrodes	Oxidation at anode, reduction at cathode (same as galvanic), but driven by the applied voltage.	Oxidation at anode, reduction at cathode, occurring on their own.
Examples / uses	Electrolysis of water or molten NaCl, electroplating, electrorefining.	Daniell cell, dry cell, lead-acid battery during discharge, fuel cells.

Point	Electrolytic cell	Voltaic (galvanic) cell
Energy change	Electrical energy → chemical energy	Chemical energy → electrical energy
Reaction	Non-spontaneous (\(\Delta G > 0\)), forced by an external source	Spontaneous (\(\Delta G < 0\))
External source	Needs a battery / DC supply	Not needed; the cell itself is the source of emf
Anode	Positive electrode (oxidation)	Negative electrode (oxidation)
Cathode	Negative electrode (reduction)	Positive electrode (reduction)
Construction	Usually both electrodes in one vessel with one electrolyte	Usually two half-cells joined by a salt bridge
Examples	Electrolysis of water or fused NaCl, electroplating, electrorefining	Daniell cell, dry cell, lead storage battery (discharging)