Question

Given.$Si{O_2}$ is used to remove the impurities of $\,\,CaO$ in an ore in metallurgy.
Reason: $\,\,CaO$ is an infusible mass of basic nature. It reacts with flux $Si{O_2}$which is acidic in nature and gives a fusible mass of $CaSi{O_3}$.
A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
C. Assertion is correct but Reason is incorrect
D. Both Assertion and Reason are incorrect

Answer 1

Here $Si{O_2}$ is the impurity and is acidic in nature so in order to remove this impurity from the ore we need a basic flux and $\,\,CaO$ the flux given is a basic flux. And yes it’s true that $\,\,CaO$ is an infusible mass basic in nature and on reaction with $Si{O_2}$ it produces slag which is a low fusible substance produced by the reaction of flux with impurities during extraction of metals.

Complete step by step answer:
As we all know that in the metallurgy of iron, limestone ($CaC{O_3}$) acts as a flux and forms calcium silicate ($CaSi{O_3}$) that is the slag.
$CaC{O_3}\, \to CaO\, + \,C{O_2}\, \uparrow$
$\mathop {CaO + Si{O_2}}\limits_{\left( {FLUX} \right)} \to \mathop {CaSi{O_3}}\limits_{\left( {SLAG} \right)}$
In a blast furnace at a temperature of $1273K$ the slagging operation takes place. At the base the molten iron is collected under the slag. This iron is known as the pig iron. And this pig iron contains approximately about four percent of carbon with many other impurities like S, P, Si, Mn, etc.

The metal iron is collected from slag by pressing under rollers.

The solution of the given problem is option (a) that says, both assertion and reason are correct and that the reason is the correct explanation of the assertion.

Note: This reaction belongs to the process of extraction of Iron (Fe) from $F{e_2}{O_3}$ or $F{e_3}{O_4}$ in the blast furnace and this reaction particularly takes place at the zone of slag formation. Such reactions are known as slagging operations in metallurgy. In such cases a flux (basic if the impurity is acidic and acidic if the impurity is basic) is used to convert the impurity into slag.