Question

The electrolytic reduction process is used for the extraction of:
A.Highly electropositive metals
B.Metalloids
C.Less active metals
D.Transition metals

Answer 1

Hint: Basically, the metals that are placed at high positions in the activity series cannot be produced by any of the methods. So, they are obtained by electrolytic reduction of their molten oxides or chlorides. It is a type of electrolysis in which electric current is passed through an ionic substance which further produces a chemical reaction at the electrodes.

Complete step by step answer:
Electrolysis is basically a process that is helpful in the study of chemical reactions to obtain pure elements. It is defined as a process of decomposing ionic compounds into their elements by passing a direct current through the compound in a fluid form. Moreover, the cations are reduced at cathode and the anions are oxidized at the anode. It is usually done in a vessel named electrolytic cell.
Now, electrolytic reduction is a type of electrolysis in which electric current is passed through an ionic substance which further produces a chemical reaction at the electrodes. Basically, this process is used for the extraction of highly electropositive metals. Certain metals like Na, K, Al are obtained by this process. Now, let’s discuss some of the examples with specific reactions.
Sodium metals are obtained by the electrolysis of molten sodium chloride. The reactions are given below:
 \[2NaCl\xrightarrow{{fused}}2N{a^ + } + 2C{l^ - }\]
 $2Cl \to C{l_2} + 2e\,(at\,anode)$
 $2N{a^ + } \to 2Na\,(at\,Cathode)$
So, the resulting equation is
 $2NaCl\xrightarrow{{electrolysis}}2Na + C{l_2}$
Aluminum oxide is reduced to aluminum by the electrolysis of molten aluminum oxide
 $A{l_2}{O_3} \to 2A{l^{3 + }} + 3{O^{2 - }}$
So, the aluminum ions present in aluminum oxide go to cathode and are reduced there to aluminum atoms.
Therefore, oxides of strong electropositive metals such as Ca, Na, K, Al and Mg are very stable and it is difficult to reduce them into metallic states by carbon reduction and thus such metals are extracted by passing electricity through their fused chlorides, hydroxides or oxides.
Hence, option A is correct.

Note:It should be noted that during electrolytic reduction of molten salts, the metals are always liberated at cathode. Moreover, some specific metals such as gold and silver are obtained by treating the ore with a solution of sodium cyanide.