The name of FeCl3 · 6H2O is: Iron chloride hexahydrate.
The Correct Answer and Explanation is:
The correct name of FeCl₃ · 6H₂O is:
Iron(III) chloride hexahydrate
Explanation:
FeCl₃ · 6H₂O is an example of a hydrated ionic compound, which consists of a salt (FeCl₃) and a specific number of water molecules (6H₂O) attached to it. These water molecules are called waters of hydration and are included in the compound’s name and formula.
1. Naming the Ionic Part (FeCl₃)
The first step in naming this compound is to identify the ionic compound FeCl₃:
- Fe stands for iron, a transition metal. Transition metals can have more than one possible charge.
- Cl stands for chlorine. When forming an anion, chlorine becomes chloride, with a charge of –1.
- Since there are three chloride ions, the total negative charge is –3.
- To balance this, the iron cation must have a +3 charge.
- Therefore, the iron ion is Fe³⁺, and the name of FeCl₃ is iron(III) chloride. The Roman numeral (III) indicates the +3 oxidation state of iron.
2. Naming the Hydrate Part (· 6H₂O)
The second part of the compound is · 6H₂O, which indicates six water molecules are attached to each formula unit of iron(III) chloride. This is expressed using the Greek prefix hexa- (meaning six), followed by the word hydrate.
3. Combining the Names
Combining both parts gives the full name:
→ Iron(III) chloride hexahydrate
This name accurately reflects the compound’s composition: iron in the +3 oxidation state, three chloride ions, and six water molecules of hydration.
