Question

Consider the following electronic configuration:
Cu²⁺ = [Ar] 3d⁴4s⁰
Cu⁺ = [Ar] 3d¹⁰4s⁰
Which option is correct?

• A. Cu²⁺ is more stable in aqueous solution
• B. Cu⁺ is more stable in aqueous solution
• C. Cu⁺ and Cu²⁺ are equally stable in aqueous solution
• D. Depends upon copper salt

Answer 1

The Correct Option is A

The question involves determining the relative stability of copper ions \text{Cu}^+\ and \text{Cu}^{2+}\ in an aqueous solution based on their electronic configurations.

1. Electronic Configurations:
   • Cu²⁺: [Ar] 3d⁹ 4s⁰
   • Cu⁺: [Ar] 3d¹⁰ 4s⁰
2. Stability Analysis:
   • In aqueous solutions, the stability of an ion depends on factors such as hydration energies and the electronic configuration.
   • The electronic configuration of \text{Cu}^{2+} ([Ar] 3d⁹) is considered less stable due to an incomplete d subshell.
   • However, \text{Cu}^{2+} is stabilized in aqueous solution due to high hydration energy compared to \text{Cu}^+\.
   • The \text{Cu}^+\ ion ([Ar] 3d¹⁰) has a completely filled d subshell, which generally makes it stable. However, its relatively lower hydration energy makes \text{Cu}^+\ less stable in aqueous solution.
3. Conclusion: Cu²⁺ is more stable in an aqueous solution because of its higher hydration energy compared to Cu⁺. This is why Cu²⁺ is more commonly found in aqueous solutions.

Therefore, the correct answer is: Cu²⁺ is more stable in aqueous solution.