systematic rule for nomenclature to name Fe(NO3)2
The Correct Answer and Explanation is:
The systematic name for Fe(NO3)2 can be determined using the IUPAC (International Union of Pure and Applied Chemistry) nomenclature rules. Here’s the step-by-step process to name it:
- Identify the cation and anion:
- Fe(NO3)2 consists of the iron (Fe) cation and the nitrate (NO3-) anion. The nitrate ion is straightforward because it is a common polyatomic ion, NO3-, and it is named “nitrate.”
- Determine the charge on the cation (Fe):
- Iron can exist in two common oxidation states: +2 and +3. In this compound, we have two nitrate ions (each with a charge of -1), meaning the total negative charge is -2. Therefore, to balance the charges, the iron ion must have a +2 charge.
- Naming the metal cation (Fe):
- When a transition metal like iron can have more than one possible charge, the charge is indicated in the name using Roman numerals. In this case, iron is in the +2 oxidation state, so it is named “iron(II).”
- Combine the names:
- The cation (iron) and the anion (nitrate) are combined, with the charge of the cation indicated by Roman numerals in parentheses. So, the systematic name of Fe(NO3)2 is “iron(II) nitrate.”
Explanation:
The nomenclature system ensures clarity and consistency when naming compounds, especially those containing transition metals, which can exhibit multiple oxidation states. By using Roman numerals, we differentiate between compounds like Fe(NO3)2 (iron(II) nitrate) and Fe2(SO4)3 (iron(III) sulfate), which could otherwise be confusing. The nitrate ion, NO3-, is a well-known polyatomic ion, and its name remains the same across different compounds.
