What is the formula for cobalt(III) fluoride ?
The correct answer and explanation is:
The formula for cobalt(III) fluoride is CoF₃.
Explanation:
Cobalt(III) fluoride refers to a compound in which cobalt has a +3 oxidation state, and fluoride ions, denoted as F⁻, bond with the cobalt ion. The Roman numeral III indicates that cobalt is in a +3 oxidation state.
- Cobalt’s Oxidation State: In cobalt(III) fluoride, cobalt has a +3 charge. This is because cobalt can exhibit multiple oxidation states, including +2 and +3. In this case, the Roman numeral III tells us that the cobalt ion is Co³⁺.
- Fluoride Ion: The fluoride ion is the ionized form of fluorine, which carries a -1 charge (F⁻). Fluorine, being highly electronegative, readily forms ionic bonds by gaining an electron to become a fluoride ion.
- Formula Derivation: To determine the correct formula, we balance the total positive and negative charges in the compound.
- Cobalt in the +3 oxidation state has a +3 charge.
- Fluoride ions each have a -1 charge. To balance the +3 charge from cobalt, we need three fluoride ions.
- Therefore, the compound’s formula is CoF₃, where three fluoride ions are needed to neutralize the +3 charge from one cobalt ion.
- Ionic Bonding: In cobalt(III) fluoride, the cobalt ions are electrostatically attracted to the fluoride ions due to their opposite charges. The ionic bond formed between Co³⁺ and F⁻ holds the compound together in a stable structure.
Cobalt(III) fluoride is a solid compound, often used in certain industrial applications like electroplating and as a catalyst in chemical reactions.