Which of the following is epsom salt ?

Options

A. `2CaSO_4 . H_2O`
B. `MgSO_4. 7H_2O`
C. `MgSO_4. 2H_2O`
D. `BaSO_4. 2H_2O`

Answer

To determine which of the following compounds is Epsom salt, we need to identify the correct chemical formula associated with Epsom salt.

### Step-by-Step Solution:

1. **Understanding Epsom Salt**:
- Epsom salt is commonly known as Magnesium Sulfate Heptahydrate.
- Its chemical formula is \( \text{MgSO}_4 \cdot 7\text{H}_2\text{O} \).

2. **Analyzing the Options**:
- We need to evaluate the given options to find out which one corresponds to \( \text{MgSO}_4 \cdot 7\text{H}_2\text{O} \).

3. **Option Evaluation**:
- **Option 1**: \( 2\text{CaSO}_4 \cdot \text{H}_2\text{O} \)
- This is the formula for Plaster of Paris (POP), which is not Epsom salt.
- **Option 2**: \( \text{MgSO}_4 \cdot 7\text{H}_2\text{O} \)
- This is indeed the correct formula for Epsom salt.
- **Option 3**: \( \text{MgSO}_4 \cdot 2\text{H}_2\text{O} \)
- This is Magnesium Sulfate Dihydrate, not Epsom salt.
- **Option 4**: \( \text{BaSO}_4 \cdot 2\text{H}_2\text{O} \)
- This is Barium Sulfate Dihydrate, which is also not Epsom salt.

4. **Conclusion**:
- After evaluating all the options, the only compound that matches the definition of Epsom salt is **Option 2**: \( \text{MgSO}_4 \cdot 7\text{H}_2\text{O} \).

### Final Answer:
The correct answer is **Option 2: \( \text{MgSO}_4 \cdot 7\text{H}_2\text{O} \)**.