Topic: Trends: ionization enthalpy, oxidation states, atomic radii· d- and f-Block Elements

The stability of Cu^2+ is more than Cu^+ salts in aqueous solution due to -

1. second ionisation enthalpy.

2. first ionisation enthalpy.

3. enthalpy of atomization.

4. hydration energy.

Doubtly Asked 30 Oct 2026 NEET UG 2023 Practice test neet Save WhatsApp Report

1 answer

Best answer

Answer: 4. hydration energy.

Key idea: Stability in aqueous solution depends on the overall enthalpy change, where hydration enthalpy often dominates.

\(\mathrm{Cu^+}\) (3d\(^{10}\)) looks more stable, and the second ionisation enthalpy of Cu is very high. But \(\mathrm{Cu^{2+}}\) has a much higher (more negative) hydration energy because of its smaller size and higher charge. This large hydration energy more than makes up for the second ionisation enthalpy, so \(\mathrm{Cu^{2+}}\) is more stable in water. Option 4.

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

Was this answer helpful?

The stability of Cu^2+ is more than Cu^+ salts in aqueous solution due to -

1 answer

Your answer