Assertion: Concentrated aqueous solution of `CuCl_(2)` is green in colour.
Reason : The solution contains two complex ions i.e., `[Cu(H_(2)O)_(4)]^(2+) and [CuCl_(4)]^(2-)` in equilibrium.

Options

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

Answer

To solve the assertion and reason question regarding the color of concentrated aqueous solution of CuCl₂, we can break it down step by step.

### Step 1: Understand the Assertion
The assertion states that concentrated aqueous solution of CuCl₂ is green in color.

**Explanation**: When CuCl₂ is dissolved in water, it dissociates into its ions. The presence of copper ions (Cu²⁺) in solution is known to impart color due to their electronic transitions.

**Hint**: Recall the role of transition metal ions in imparting color to solutions due to d-d transitions.

### Step 2: Analyze the Reason
The reason provided states that the solution contains two complex ions: [Cu(H₂O)₄]²⁺ and [CuCl₄]²⁻ in equilibrium.

**Explanation**: In an aqueous solution, copper ions can form complexes with water and chloride ions. The complex [Cu(H₂O)₄]²⁺ is formed when copper ions coordinate with water molecules, while [CuCl₄]²⁻ is formed when copper ions coordinate with chloride ions. The equilibrium between these two complexes contributes to the overall color of the solution.

**Hint**: Consider how the formation of different complexes can influence the color of the solution.

### Step 3: Conclusion
Both the assertion and the reason are correct. The assertion is correct because the concentrated aqueous solution of CuCl₂ is indeed green in color. The reason is also correct as it explains that the color arises from the presence of two complex ions in equilibrium.

**Final Statement**: Therefore, the assertion is true, and the reason is also true, and it correctly explains the assertion.

### Summary
- **Assertion**: Concentrated aqueous solution of CuCl₂ is green in color. (True)
- **Reason**: The solution contains two complex ions, [Cu(H₂O)₄]²⁺ and [CuCl₄]²⁻ in equilibrium. (True)

Both the assertion and reason are correct, and the reason provides a valid explanation for the assertion.