Question

Most electropositive metals are obtained from their ores by:
A. Autoreduction
B. Smelting with carbon
C. Electrolysis of fused salt
D. Thermal decomposition

Answer 1

We must remember that the salts of electropositive metals easily dissociates in water and these metals form positive ions in the solution. Some examples for electropositive metals are ${\text{L}}{{\text{i}}^{\text{ + }}}{\text{,N}}{{\text{a}}^{\text{ + }}}{\text{,}}{{\text{K}}^{\text{ + }}}{\text{,B}}{{\text{e}}^{{\text{2 + }}}}{\text{,M}}{{\text{g}}^{{\text{2 + }}}}{\text{ and C}}{{\text{a}}^{{\text{2 + }}}}$.

Complete answer:
Let’s start with understanding electropositive metals, electropositive metals are the one which tends to lose electrons and form a positive ion. As for why they lose electrons, well they lose electrons to complete their octet and achieve a noble gas configuration. For example, we are having sodium $\left( {Na} \right)$ having atomic number 11. The nearest noble gas is neon $\left( {Ne} \right)$ having atomic number 10 so, to achieve the same electronic configuration as neon, sodium loses an electron forming $N{a^ + }$ ion. Such metals are known as electropositive metals.
Now coming back to the question, we must know that electrolysis is the method through which most electropositive metals are obtained from their ore.
Most of the electropositive metal ores fused salt gets dissociated in water and forms ions, for example $NaCl$ forms $N{a^ + }$ and $C{l^ - }$. So to convert $N{a^ + }$to $Na$, we required an electron. Now, in the case of electrolysis, there are two rods that are connected by a source of electricity, say battery. The negative side is connected to the cathode and the positive is the anode. The two rods are dipped into the solution containing the fused salt of ore say $NaCl$. Now, due to electricity passing the $N{a^ + }$ ion will move towards the cathode where it receives an electron and converts to Sodium metal and deposits below the cathode. This sodium is then collected and hence the electropositive metal is being extracted.
Therefore, we can conclude that most electropositive metals are obtained from their ores by electrolysis of fused salt.
So, we can conclude that the correct answer is the option number C.

Note:
We must know that electrolysis is one of the many methods which are widely used in industry, it is used not only for the extraction of metals but also to reduce the impurities in the metal. This process is used in the medical field as well as for permanent removal of hair, etc. Even though such applications have some side effects but in the long run it is good.