Here's why:
* Copper(II) ions (Cu²⁺) are blue in aqueous solution.
* When CuCl₂ dissolves in water, it dissociates into Cu²⁺ and Cl⁻ ions.
* The blue color arises from the interaction of the Cu²⁺ ions with water molecules. These interactions involve the formation of coordination complexes, which absorb certain wavelengths of light, resulting in the blue color.
Note: The exact shade of blue can vary depending on the concentration of the solution.
