Question

Cuprous ion is colourless while cupric ion is coloured because:

• A. Both have half-filled p- and d-orbitals.
• B. Cuprous ion has an incomplete d-orbital and cupric ion has a complete d-orbital.
• C. Both have unpaired electrons in the d-orbitals.
• D. Cuprous ion has a complete d-orbital and cupric ion has an incomplete d-orbital.

Hint:

A complete d-orbital configuration prevents d-d transitions, making the ion colourless.

Answer 1

The Correct Option is D

Step 1: Understanding electronic configurations.
- \( Cu^+ \) has a complete 3d\(^{10}\) configuration (no d-d transitions, thus colourless).
- \( Cu^{2+} \) has a 3d\(^9\) configuration (allows d-d transitions, thus coloured).