Question

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 :

• A. (A) is not correct but (R) is correct
• B. Both ( A ) and ( R ) are correct and ( R ) is not the correct explanation of ( A )
• C. Both (A) and (R) are correct but (R) is the correct explanation of (A)
• D. (A) is correct but (R) is not correct

Hint:

Carefully consider the relationship between the assertion and the reason. Even if both statements are individually correct, the reason may not necessarily be the correct explanation for the assertion.

Answer 1

The Correct Option is B

Step 1: Analyze Assertion (A)
Gypsum (\(\text{CaSO}_4\cdot 2\text{H}_2\text{O}\)) is used for making fireproof wall boards. When heated, gypsum loses water and forms plaster of Paris, which is a good fire-resistant material. Hence, assertion (A) is correct.
Step 2: Analyze Reason (R)
Gypsum is unstable at high temperatures as it loses water molecules upon heating. Hence, Reason (R) is also correct.
Step 3: Determine the Relationship between (A) and (R)
While both statements are correct, the reason gypsum is used in fireproof wall boards is not simply because it's unstable at high temperatures. It's because the water molecules present in gypsum act as a fire retardant. When exposed to fire, the water molecules are released as steam, absorbing a significant amount of heat and preventing the spread of the fire. This process makes the wall board fire resistant.
Therefore, (R) is not the correct explanation for (A).