Question

Assertion :Concentrated aqueous solution of $Cu{Cl}_2$ is green in colour. Reason: The solution contains two complex ions i.e., ${\left[Cu{\left(H_{2}O\right)}_4\right]}^{2+}$ and ${\left[{CuCl}_4\right]}^{2-}$ in equilibrium.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

The solution contains two complex ions i.e., $\left[Cu\right(H_{2}O{)}_4{]}^{2+}and[CuC{l}_4{]}^2$ in equilibrium.
The $C{u}^{2+}$ ion has $3d^9$ electronic configuration and one contains 1 unpaired electron.
Hence, concentrated aqueous solution of $CuC{l}_2$ is green in colour.