Iron(II) iodate Express your answer as a chemical formula.
The Correct Answer and Explanation is:
Correct Answer: Fe(IO₃)₂
Explanation (Approx. 300 Words):
To determine the chemical formula of iron(II) iodate, we need to understand the charges of the ions involved and how they combine to form a neutral compound.
Step 1: Identify the Ions
- Iron(II):
The Roman numeral “II” indicates the oxidation state of the iron ion.
- Iron(II) means Fe²⁺, which is a cation (positively charged ion).
- Iodate:
Iodate is a polyatomic anion.
- Its formula is IO₃⁻ and it carries a -1 charge.
Step 2: Balance the Charges
In an ionic compound, the total positive and negative charges must balance (equal zero overall charge).
- One Fe²⁺ ion has a +2 charge.
- One IO₃⁻ ion has a -1 charge.
To balance:
- We need two IO₃⁻ ions (each -1) to balance one Fe²⁺ ion (+2).
Mathematically:
- (+2) + 2×(-1) = 0
Step 3: Write the Formula
Since we need:
- 1 Fe²⁺ ion
- 2 IO₃⁻ ions
We write the formula as:
Fe(IO₃)₂
- Parentheses are used around the IO₃ because there are two of them, and IO₃ is a polyatomic ion.
- The subscript “2” outside the parentheses indicates two iodate ions are present.
Summary
The compound iron(II) iodate consists of one iron(II) cation (Fe²⁺) and two iodate anions (IO₃⁻), resulting in the chemical formula Fe(IO₃)₂. This compound is ionic, meaning it is held together by the electrostatic attraction between the positively charged iron ion and the negatively charged iodate ions. Understanding oxidation states and polyatomic ions is essential for correctly writing formulas for such compounds.