The compound which does not exist as hydrate form

Options

A. Ferrous sulphate
B. Copper sulphate
C. Magnesium sulphate
D. Sodium Chloride

Answer

To determine which compound does not exist in a hydrate form, we will analyze each option provided:

1. **Ferrous Sulfate (FeSO4)**:
- Ferrous sulfate commonly exists as a hydrate known as ferrous sulfate heptahydrate (FeSO4·7H2O).
- Therefore, FeSO4 does exist in a hydrate form.

2. **Copper Sulfate (CuSO4)**:
- Copper sulfate exists as a hydrate known as copper sulfate pentahydrate (CuSO4·5H2O).
- Thus, CuSO4 also exists in a hydrate form.

3. **Magnesium Sulfate (MgSO4)**:
- Magnesium sulfate exists as a hydrate known as magnesium sulfate heptahydrate (MgSO4·7H2O).
- Hence, MgSO4 exists in a hydrate form as well.

4. **Sodium Chloride (NaCl)**:
- Sodium chloride does not have a water of crystallization associated with it and does not exist in a hydrate form.
- Therefore, NaCl is the compound that does not exist as a hydrate.

Based on the analysis above, the compound that does not exist as a hydrate form is **D. NaCl**.

### Summary of Steps:
1. Identify and analyze each compound to check for the presence of water of crystallization.
2. Confirm that FeSO4, CuSO4, and MgSO4 all exist as hydrates.
3. Conclude that NaCl does not exist as a hydrate.