Question

Which of the following metal ions is most likely to exist as a stable eight-coordinate complex with fluoride? Cu2+ Cu+ Fe3+ Ag3+ U4+

Answer 1

Answer:

U⁴⁺  

Explanation:

Fluorine stabilizes metals in higher oxidation states with high M:F ratios.

Hard acids prefer to bind to hard bases.

U⁴⁺ is the hardest acid in the list and F⁻ is a hard base, so an eight-coordinate complex of U⁴⁺ is the most stable.