Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Gypsum is used for making fireproof wall boards.
Reason (R) : Gypsum is unstable at high temperatures.
In the light of the above statements, choose the correct answer from the options given below :
Assertion (A) : Gypsum is used for making fireproof wall boards.
Reason (R) : Gypsum is unstable at high temperatures.
In the light of the above statements, choose the correct answer from the options given below :
- (A)Both (A) and (R) are correct but (R) is not the correct explanation of (A).✓ Correct
- (B)(A) is correct but (R) is not correct.
- (C)(A) is not correct but (R) is correct.
- (D)Both (A) and (R) are correct and (R) is the correct explanation of (A).
Answer: (A)
Solution
Gypsum, , is used in fireproof wall boards, so the assertion is true. On strong heating it does lose its water of crystallisation and break down, so the reason is also a true statement in itself. The fireproofing, however, works because the bound water is driven off endothermically and the escaping vapour carries heat away and shields the wall behind it, rather than merely because the solid is thermally unstable. Both statements are correct, but the reason does not account for the assertion.
JEE Main · 2023 · 01 Feb 2023 · Shift 2 · Single correct option