Question

Statement-1: \[Si{O_2}\] is used as an acidic flux in metallurgy
Statement-2: \[Si{O_2}\] removes basic impurities forming a slag.
(A) Statements-1 is True, Statement-2 is True; Statement-2 is the correct explanation for Statement-1.
(B) Statements-1 is True, Statement-2 is True; Statement-2 is not the correct explanation for Statement-1.
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True.

Answer 1

Hint: Flux is a chemical substance that is added for the extraction of metal. Addition of flux in a reaction can lead to the formation of slag. Flux will form slag with those impurities which are more soluble in it. \[Si{O_2}\] is used to remove basic impurities in the metallurgy.

Complete Solution :
Before moving onto the question, we must understand the term flux and slag. Flux is a chemical substance which is used to remove impurities. Different kinds of Flux can be used to remove different types of impurities. By removing impurities pure metal will be obtained at the end of the end of the reaction.
- For example, we use iron ore as a flux during smelting of copper, other fluxes like borax, lime, sodium carbonate etc. are used during different processes.
- After the separation of the desired metal from its ore, slag will be obtained as the by-product of the reaction.
- So, \[Si{O_2}\] based flux increases heat input, and decreases the mechanical properties of the weld.
Thus, to remove the basic impurities, acidic flux \[Si{O_2}\] is used.
\[Si{O_2} + CaO \to CaSi{O_3}\] (slag)
Here, the \[CaSi{O_3}\] is the slag formed.
Clearly, the correct answer is Statements-1 is True, Statement-2 is True; Statement-2 is the correct explanation for Statement-1.
So, the correct answer is “Option A”.

Note: - Different kinds of Flux can be used to remove different types of impurities. Flux can be of two types acidic and basic, depending on the type of impurity we want to remove.
- Acidic flux will be used for the removal of basic impurities like Calcium oxide and Magnesium oxide, while basic flux is used for the removal of the acidic impurities like Silicon dioxide and Diboron trioxide.
- Here we have the impurity of Silicon dioxide, \[Si{O_2}\] which we can remove by using a basic flux like Calcium oxide, \[CaO\].