Question

Which of the following processes involves smelting?
A. $2PbS + 3{O_2} \to 2Pb{O_2} + 2S{O_2}$
B. $A{l_2}{O_3}.2{H_2}O \to A{l_2}{O_3} + 2{H_2}O$
C. $F{e_2}{O_3} + CO \to 2Fe + 2C{O_2}$
D. $C{r_2}{O_3} + 2Al \to A{l_2}{O_3} + 2Cr + Heat$

Answer 1

We need to remember that the smelting is a process. This process, a metal is obtained either as an element or as a simple compound from its ore. The ore obtained by the process involves heating beyond its melting point, in the presence of oxidizing agents such as air or reducing agents such as coke. Smelting took place in a large clay furnace.

Complete step by step answer:
We must have to know that the smelting is a form of extraction of metals. Ores contains oxygen that binds with carbon at high temperatures because of the lower potential energy of the carbon dioxide $(C{O_2})$ bonds.
As we know that the two stages of carbon oxidation is, first, oxygen present in the air that combust carbon to produce carbon monoxide $(CO)$ and in second stage, the product carbon monoxide reacts with ore and removes it’s one of the oxygen atoms and releasing carbon dioxide $(C{O_2})$.
Let us see the options one by one to seek out the correct one.
If you see the option A. $2PbS + 3{O_2} \to 2Pb{O_2} + 2S{O_2}$, the product obtained is $Pb{O_2}$, but in smelting process a metal is obtained, so this is not the correct one.
Option B. $A{l_2}{O_3}.2{H_2}O \to A{l_2}{O_3} + 2{H_2}O$
Also this is not a correct option. In the above equation, the reactant gives the products $A{l_2}{O_3}\& H_2^{}O$. And the reactants do not react with oxygen.
Option C. $F{e_2}{O_3} + CO \to 2Fe + 2C{O_2}$
The ore $F{e_2}{O_3}$ reacts with carbon monoxide $(CO)$ to give the raw element $Fe$. And removes it’s oxygen atoms and releases carbon dioxide $(C{O_2})$. This is the smelting process. But let’s see if another option is correct or not.
Option D. $C{r_2}{O_3} + 2Al \to A{l_2}{O_3} + 2Cr + Heat$
This is also not a correct option, because the smelting process gives free metal from ores, but the above equation, aluminium $(Al)$ is the reactant which gives it’s one of oxide $(A{l_2}{O_3})$.

So, the correct answer is Option C.

Note: We need to remember that the smelting process causes serious effects on the environment and the workers who work in the industry. In contrast to smelting, a substance changes from the solid state .