Gypsum on heating at 393K produces

Options

A. `CaSO_(4). 0.5H_(2)O`
B. Anhydrous `CaSO_(4)`
C. Dead burnt plaster
D. `CaSO_(4).5H_(2)O`

Answer

To solve the question regarding what gypsum produces when heated at 393 K, we can follow these steps:

### Step-by-Step Solution:

1. **Identify Gypsum's Chemical Formula**:
Gypsum is chemically represented as \( \text{CaSO}_4 \cdot 2\text{H}_2\text{O} \). This indicates that gypsum contains calcium sulfate and two molecules of water.

2. **Understand the Heating Process**:
When gypsum is heated, it undergoes a dehydration reaction. The water molecules are released, and the compound transforms into a different form.

3. **Heating Gypsum at 393 K**:
At 393 K, gypsum loses one molecule of water. The reaction can be represented as:
\[ \text{CaSO}_4 \cdot 2\text{H}_2\text{O} \xrightarrow{393 K} \text{CaSO}_4 \cdot 0.5\text{H}_2\text{O} \]
This product is known as plaster of Paris (POP).

4. **Conclusion**:
Therefore, when gypsum is heated at 393 K, it produces \( \text{CaSO}_4 \cdot 0.5\text{H}_2\text{O} \), which is also referred to as plaster of Paris.

### Final Answer:
Gypsum on heating at 393 K produces \( \text{CaSO}_4 \cdot 0.5\text{H}_2\text{O} \) (plaster of Paris).

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