The correct name for Feo is
A) iron oxide
B) iron oxide.
C) iron monoxide
D) Iron(II)oxide.
E) ironi) oxide.
The correct answer and explanation is :
The correct name for FeO is:
D) Iron(II) oxide.
Explanation:
FeO is a compound consisting of iron (Fe) and oxygen (O). To name this compound correctly using IUPAC (International Union of Pure and Applied Chemistry) nomenclature, several rules must be followed, particularly because iron is a transition metal that can form more than one type of positive ion (cation).
1. Identify the ions and their charges:
- Oxygen usually forms a -2 ion (O²⁻).
- In FeO, there is one iron atom and one oxygen atom. Since oxygen has a charge of -2, the iron must have a charge of +2 to balance the compound to neutral. So, the iron ion here is Fe²⁺.
2. Name the metal with its oxidation number:
Because iron can have multiple oxidation states (Fe²⁺ and Fe³⁺), the name must specify which form is present. This is done using Roman numerals in parentheses immediately after the name of the metal.
- Fe²⁺ is called Iron(II)
- Fe³⁺ is called Iron(III)
Since the Fe in FeO is Fe²⁺, we name it Iron(II).
3. Name the non-metal as an -ide:
The anion (O²⁻) is named as “oxide”.
4. Put it all together:
Combining the cation and anion names gives us Iron(II) oxide.
Why Other Options Are Incorrect:
- A) iron oxide – Incomplete and ambiguous. Doesn’t specify the oxidation state.
- B) iron oxide. – Same as A, with incorrect punctuation.
- C) iron monoxide – This naming style (prefixes like mono-) is used for nonmetal–nonmetal compounds, not for metal–nonmetal compounds.
- E) ironi) oxide. – This is misspelled and incorrectly formatted.
Summary:
FeO is correctly named Iron(II) oxide because it contains iron in the +2 oxidation state and oxygen in the -2 state. The Roman numeral ensures clarity in compounds with metals that have multiple oxidation states.