How many hydrogen bonded water molecules are present in blue vitriol?

Options

A. Zero
B. One
C. Four
D. Five

Answer

To determine how many hydrogen-bonded water molecules are present in blue vitriol (CuSO4·5H2O), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Formula of Blue Vitriol**:
The chemical formula for blue vitriol is CuSO4·5H2O. This indicates that there are five water molecules associated with each copper sulfate unit.

2. **Understand the Role of Water Molecules**:
In the complex, out of the five water molecules, four act as ligands that coordinate with the copper ion (Cu²⁺). This means they are directly bonded to the copper ion.

3. **Identify the Remaining Water Molecule**:
The fifth water molecule is not coordinated to the copper ion; instead, it is involved in hydrogen bonding. This water molecule is typically found outside the coordination sphere of the copper complex.

4. **Count the Hydrogen-Bonded Water Molecules**:
Since only the fifth water molecule is involved in hydrogen bonding, we conclude that there is **1 hydrogen-bonded water molecule** in blue vitriol.

### Final Answer:
There is **1 hydrogen-bonded water molecule** present in blue vitriol (CuSO4·5H2O).

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