Question

The electronic configuration of Cu(II) is 3d⁹ whereas that of Cu(I) is 3d¹⁰. Which of the following is correct ?

• A. Cu(II) is less stable
• B. Stability of Cu(I) and Cu(II) depends on nature of copper salts
• C. Cu(II) is more stable
• D. Cu(I) and Cu(II) are equally stable

Answer 1

The Correct Option is C

This inquiry concerns the comparative stability of copper in its +1 (Cu(I)) and +2 (Cu(II)) oxidation states under standard conditions. Stability assessment requires examination of electronic configurations and empirical data for copper salts.

Electronic Configuration:

• Cu(II) exhibits a 3d⁹ electronic configuration.
• Cu(I) possesses a 3d¹⁰ electronic configuration.

Cu(I)'s d¹⁰ configuration is a fully filled d-orbital. While a full or half-full d-orbital is typically associated with increased stability, Cu(II)'s d⁹ configuration, though not fully filled, benefits from other stabilizing factors.

Stability of Copper Oxidation States:

The stability of an element's oxidation states is influenced by several phenomena, including lattice energy, solvation energy, and the Jahn-Teller effect:

• Jahn-Teller Effect: The d⁹ configuration of Cu(II) is susceptible to Jahn-Teller distortion, which results in stabilization.
• Coordination Chemistry: In aqueous solutions, Cu(II) demonstrates greater stability due to a higher hydration energy compared to Cu(I).

In light of these factors, Cu(II) generally exhibits superior stability over Cu(I) in aqueous environments. Empirical observations of copper salts frequently indicate that Cu(II) compounds are more prevalent and stable.

Conclusion:

The definitive answer is: Cu(II) is more stable. This conclusion is substantiated by the enhanced stability of Cu(II), attributable to phenomena such as the Jahn-Teller effect and elevated hydration energy.