Assertion : `CuSO_(4).5H_(2)O` has one hydrogen-bonded molecule of water.
Reason : The four molecules of water are coordinated in `CuSO_(4).5H_(2)O`.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer

To solve the question regarding the assertion and reason related to `CuSO4.5H2O`, we can break down the problem into several clear steps:

### Step 1: Understand the Composition of `CuSO4.5H2O`
`CuSO4.5H2O` is a hydrated form of copper(II) sulfate, which means it contains copper sulfate along with five water molecules. The formula indicates that there are five water molecules associated with each formula unit of copper sulfate.

**Hint:** Identify the components of the compound and their significance in the structure.

### Step 2: Analyze the Assertion
The assertion states that `CuSO4.5H2O` has one hydrogen-bonded molecule of water. To evaluate this, we need to consider how the water molecules are arranged in the structure of the compound.

**Hint:** Recall that hydrogen bonding occurs between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

### Step 3: Examine the Reason
The reason states that the four molecules of water are coordinated in `CuSO4.5H2O`. Coordination refers to the way these water molecules are bonded to the copper ion (Cu²⁺) in the structure. In `CuSO4.5H2O`, four water molecules are indeed coordinated to the copper ion.

**Hint:** Coordination involves the formation of coordinate bonds, where the water molecules donate lone pairs of electrons to the metal ion.

### Step 4: Visualize the Structure
In the structure of `CuSO4.5H2O`, the four coordinated water molecules form a square planar geometry around the copper ion. The fifth water molecule interacts with the sulfate ion through hydrogen bonding. This confirms that there is indeed one hydrogen-bonded water molecule.

**Hint:** Drawing the structure can help visualize how the water molecules are arranged around the copper ion and how hydrogen bonding occurs.

### Step 5: Conclusion
Both the assertion and the reason are true. The assertion correctly states that there is one hydrogen-bonded water molecule, and the reason accurately describes the coordination of the four water molecules with the copper ion. Therefore, the reason provides a correct explanation for the assertion.

**Hint:** When evaluating assertion-reason questions, ensure that both statements are true and that the reason logically explains the assertion.

### Final Answer
Both the assertion and reason are true, and the reason is the correct explanation of the assertion. Thus, the answer is option A.