GKFix MCQ Question

How does the Jahn-Teller effect potentially influence the hydration enthalpy of Cu2+ (d9)?

• A. It makes the ion perfectly spherical.
• B. It prevents hydration from occurring.
• C. It only affects the color, not the enthalpy.
• D. It causes a distortion in the hydrated ion's geometry, affecting the crystal field stabilization energy and thus the hydration enthalpy.