Blue vitriol has:(A) Ionic bond(B) Coordinate bond(C) Hydrogen bond(D) All of the above

Blue vitriol is another name for **copper(II) sulfate pentahydrate**, chemically represented as **CuSO₄·5H₂O**.

Let’s analyze the bonding in this compound:

1. **Ionic bond**:
Copper(II) sulfate consists of copper ions (**Cu²⁺**) and sulfate ions (**SO₄²⁻**), which are held together by ionic bonds. The attraction between the positively charged copper ion and the negatively charged sulfate ion forms a strong ionic bond.

- **Present** in the compound.

2. **Coordinate bond**:
In the structure of CuSO₄·5H₂O, the water molecules surround the Cu²⁺ ion. Four of these water molecules are directly attached to the copper ion through **coordinate bonds**, where each oxygen atom from water donates a lone pair of electrons to the Cu²⁺ ion.

- **Present** in the compound.

3. **Hydrogen bond**:
The water molecules in CuSO₄·5H₂O are also involved in **hydrogen bonding** with the sulfate ion (SO₄²⁻) or with other water molecules. Hydrogen bonds occur between the hydrogen atom of one water molecule and the oxygen atom of another, stabilizing the structure.

- **Present** in the compound.

Thus, **all three types of bonds**—ionic, coordinate, and hydrogen—are present in blue vitriol.

### Correct answer: **(D) All of the above**