Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : $$Cu^{2+}$$ in water is more stable than $$Cu^+$$.
Reason (R) : Enthalpy of hydration for $$Cu^{2+}$$ is much less than that of $$Cu^+$$.
In the light of the above statements, choose the correct answer from the options given below :

We need to evaluate the Assertion and Reason about the stability of copper ions in water.

Analysis of Assertion (A): "$$Cu^{2+}$$ in water is more stable than $$Cu^+$$."

This is CORRECT. In aqueous solution, $$Cu^{2+}$$ is indeed more stable than $$Cu^+$$. This is why $$Cu^+$$ ions in water undergo disproportionation: $$2Cu^+ \rightarrow Cu^{2+} + Cu$$. The reason for this stability is related to hydration enthalpy (discussed below).

Analysis of Reason (R): "Enthalpy of hydration for $$Cu^{2+}$$ is much less than that of $$Cu^+$$."

This is INCORRECT. The statement has the comparison backwards. The hydration enthalpy of $$Cu^{2+}$$ is actually much more negative (larger in magnitude) than that of $$Cu^+$$, not less. $$Cu^{2+}$$ has a higher charge density (charge/size ratio) than $$Cu^+$$, so it attracts water molecules more strongly and releases more energy upon hydration. The much larger (more negative) hydration enthalpy of $$Cu^{2+}$$ more than compensates for the higher second ionisation energy, making $$Cu^{2+}$$ thermodynamically more stable in aqueous solution.

Conclusion: The Assertion is correct, but the Reason is incorrect (it states the opposite of the truth).

The correct answer is Option (2): (A) is correct but (R) is not correct.