In `CuSO_(4).5H_(2)O` copper is coordinated to

Options

A. Five water molecules
B. Four water molecules
C. One sulphate anion
D. One water molecule

Answer

To determine how many molecules are coordinated to copper in the compound \( \text{CuSO}_4 \cdot 5\text{H}_2\text{O} \), we can follow these steps:

### Step 1: Understand the Composition of the Compound
The compound \( \text{CuSO}_4 \cdot 5\text{H}_2\text{O} \) consists of copper sulfate and five water molecules. The copper ion in this compound is in the +2 oxidation state, denoted as \( \text{Cu}^{2+} \).

**Hint:** Identify the components of the compound and their roles.

### Step 2: Identify the Coordination of Copper
In coordination chemistry, the central metal ion (in this case, \( \text{Cu}^{2+} \)) can coordinate with surrounding ligands. Here, we need to determine how many water molecules and sulfate ions are coordinating with the copper ion.

**Hint:** Recall that ligands can be water molecules or anions like sulfate.

### Step 3: Analyze the Coordination Number
The coordination number of a metal ion is the number of ligand atoms that are bonded to it. In \( \text{CuSO}_4 \cdot 5\text{H}_2\text{O} \), it has been established that copper is coordinated to four water molecules directly.

**Hint:** Consider the typical coordination numbers for \( \text{Cu}^{2+} \) and the geometry of the complex.

### Step 4: Consider the Role of the Sulfate Ion
The sulfate ion (\( \text{SO}_4^{2-} \)) is also part of the structure. However, it does not directly coordinate to the copper ion in the same manner as the water molecules. Instead, it acts more as a counterion in the structure.

**Hint:** Distinguish between direct coordination and other interactions (like ionic or hydrogen bonding).

### Step 5: Conclude the Coordination
From the analysis, we conclude that copper in \( \text{CuSO}_4 \cdot 5\text{H}_2\text{O} \) is coordinated to **four water molecules**. The fifth water molecule is involved in hydrogen bonding but does not directly coordinate to the copper.

**Final Answer:** Copper is coordinated to **4 water molecules**.