‘What is the name of the compound with the formula CoBr3 2 What is the name of the compound with the formula FeCl3 2 What is the name of the compound with the formula CuF ?’
The Correct Answer and Explanation is:
Here are the correct names for the compounds:
- CoBr₃ – Cobalt(III) bromide
- FeCl₃ – Iron(III) chloride
- CuF – Copper(I) fluoride
Explanation
The names of these compounds follow the nomenclature rules for ionic compounds, specifically transition metal halides. Transition metals can form multiple oxidation states, so Roman numerals are used in their names to indicate the specific charge of the metal ion in the compound.
1. CoBr₃ – Cobalt(III) bromide
- Cobalt is a transition metal.
- Bromide (Br⁻) has a charge of -1.
- There are 3 bromide ions, totaling a charge of -3.
- To balance this, cobalt must have a +3 charge.
- Therefore, the compound is cobalt(III) bromide.
2. FeCl₃ – Iron(III) chloride
- Iron (Fe) is also a transition metal.
- Chloride (Cl⁻) has a -1 charge.
- There are 3 chloride ions, totaling -3.
- To balance the charges, iron must be +3.
- So the compound is named iron(III) chloride.
3. CuF – Copper(I) fluoride
- Copper can have +1 or +2 charges.
- Fluoride (F⁻) is a -1 ion.
- Since there is only one fluoride ion, the copper must be +1 to balance the charge.
- Therefore, the name is copper(I) fluoride.
Key Naming Rules:
- Cation first, then anion.
- Transition metals require Roman numerals to indicate their oxidation state.
- Anions (like halides) are named by changing the ending of the element to “-ide.”
These naming conventions help chemists understand the composition and oxidation states of elements in compounds, which is essential for understanding chemical reactivity and properties.
