Question

Match the following

• A. I - B; II - C; III - A
• B. I - B; II - C; III - D
• C. I - B; II - A; III - D
• D. I - A; II - D; III - C

Hint:

Remember the sequence: \[ \text{Gypsum} \ \xrightarrow{\text{heating}} \ \text{Plaster of Paris} \ \xrightarrow{\text{strong heating}} \ \text{Dead burnt plaster} \] Gypsum is \(CaSO_4\cdot 2H_2O\), POP is \(CaSO_4\cdot 0.5H_2O\), and dead burnt plaster is anhydrous \(CaSO_4\).

Answer 1

The Correct Option is B

Step 1: Identify \(CaSO_4\cdot 2H_2O\).
\[ CaSO_4\cdot 2H_2O \] is calcium sulfate dihydrate.
It is commonly known as Gypsum.
Therefore, \[ \text{I} \rightarrow \text{B} \]

Step 2: Identify \(CaSO_4\cdot 0.5H_2O\).
\[ CaSO_4\cdot 0.5H_2O \] is calcium sulfate hemihydrate.
It is prepared by heating gypsum at about \(373\)-\(393\ K\).
This compound is known as Plaster of Paris (POP).
Therefore, \[ \text{II} \rightarrow \text{C} \]

Step 3: Identify anhydrous \(CaSO_4\).
\[ CaSO_4 \] is obtained by strongly heating gypsum.
The resulting product loses its ability to set with water and is called Dead burnt plaster.
Therefore, \[ \text{III} \rightarrow \text{D} \]

Step 4: Write the correct matching.
Combining the results, \[ \text{I - B,\ \ II - C,\ \ III - D} \]

Step 5: Final conclusion.
Hence, the correct matching is \[ \boxed{\text{I - B;\ II - C;\ III - D}} \] Therefore, the correct option is (2).