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Electrochemistry — Chemistry STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 ScienceChemistryElectrochemistry3 Marks
Question
What is Electrolytic cell? Explain simplest electrolytic cell in details?
✓

Answer

→ In an electrolytic cell external source of voltage is used to bring about a chemical reaction.
→ The electrochemical processes are of great importance in the laboratory and the chemical industry.
→ One of the simplest electrolytic cell consists of two copper strips dipping in an aqueous solution of copper sulphate.
→ If a DC voltage is applied to the two electrodes, then $Cu ^{+2}$ ions discharged at the cathode (negatively charged) and the following reaction takes place :
$
Cu ^{2+}( aq )+2 e ^{-} \rightarrow Cu ( s )
$
→ Copper metal is deposited on the cathode. At the anode, copper is converted into $Cu ^{+2}$ ions by the reaction :
$
Cu ( s ) \rightarrow Cu ^{2+}( s )+2 e ^{-}
$
→ Thus copper is dissolved (oxidised) at anode and deposited (reduced) at cathode.
→ This is the basis for an industrial process inwhich impure copper is converted in to copper of high purity. The impure copper is made theanode that dissolves on passing current andpure copper is deposited at the cathode.
→ Many metals like Na, Mg, Al, etc. are produced on large scale by electrochemical reduction of their respective cations where no suitable chemical reducing agents are available for this purpose.
→ Sodium and magnesium metals are produced by the electrolysis of their fused chlorides and aluminium is produced by electrolysis of aluminium oxide in presence of cryolite.

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