What is the correct name for the ionic compound, CoF3?

Question

? cobalt fluoride
? cobalt(II) fluoride
? cobalt(III) trifluoride
? trifluoride cobaltide
? cobalt(III) fluoride

Answer 1

The correct name for the ionic compound CoF3 is cobalt(III) fluoride.

This is because cobalt (Co) can have multiple oxidation states, and in this case, the presence of three fluoride ions (F⁻) indicates that cobalt is in the +3 oxidation state. Thus, the name includes the (III) designation to reflect this oxidation state.