The correct name for the ionic compound Fe2O3 is
a) diiron trioxide
b) iron oxide
c) iron (III) oxide
d) iron (II) oxide
The Correct Answer and Explanation is :
The correct name for the ionic compound Fe₂O₃ is c) iron (III) oxide.
Explanation:
- Understanding the Compound: The formula Fe₂O₃ represents a compound composed of two elements: iron (Fe) and oxygen (O). The compound is ionic, meaning the iron and oxygen ions are held together by electrostatic forces of attraction.
- Oxidation States: To determine the correct name, we need to identify the oxidation states of the elements involved. Oxygen (O) typically has an oxidation state of -2 in most compounds. In Fe₂O₃, there are three oxygen atoms, so the total negative charge from the oxygen ions is: 3×(−2)=−63 \times (-2) = -6 To balance the total charge, the two iron (Fe) atoms must contribute a total positive charge of +6. Therefore, each iron atom must have an oxidation state of +3: 2×(+3)=+62 \times (+3) = +6 This means that the iron in Fe₂O₃ is in the +3 oxidation state, so the compound is named iron (III) oxide.
- IUPAC Naming: The IUPAC (International Union of Pure and Applied Chemistry) naming convention dictates that for transition metals, we indicate the oxidation state of the metal using Roman numerals in parentheses. Iron can form multiple oxidation states, including +2 and +3, so it’s important to specify which one is present in the compound.
- Incorrect Options:
- a) diiron trioxide: This name incorrectly suggests the compound contains two iron atoms and three oxygen atoms, but it does not specify the oxidation state of iron.
- b) iron oxide: This name is too general, as it doesn’t specify the oxidation state of iron. Both FeO (iron (II) oxide) and Fe₂O₃ (iron (III) oxide) are commonly referred to as “iron oxide,” but they differ in their chemical properties.
- d) iron (II) oxide: This name is for a different compound, FeO, where iron has an oxidation state of +2.
Thus, the correct name for Fe₂O₃ is iron (III) oxide.