The number of ions formed on dissolving one molecule of `FeSO_(4)(NH_(4))_(2)SO_(4).6H_(2)O` is

Options

A. 4
B. 5
C. 3
D. 6

Answer

To determine the number of ions formed when one molecule of `FeSO₄(NH₄)₂SO₄·6H₂O` (Mohr's salt) is dissolved, we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Components of the Compound**:
The compound `FeSO₄(NH₄)₂SO₄·6H₂O` consists of:
- 1 iron (Fe)
- 2 ammonium ions (NH₄)
- 2 sulfate ions (SO₄)
- 6 water molecules (H₂O)

2. **Dissociation of the Compound**:
When the compound dissolves in water, it dissociates into its constituent ions:
- Iron (Fe) will dissociate as Fe²⁺.
- Each ammonium sulfate (NH₄)₂SO₄ will dissociate into 2 NH₄⁺ and 1 SO₄²⁻.
- The water molecules do not dissociate into ions, so they will not be counted.

3. **Count the Ions**:
From the dissociation:
- 1 Fe²⁺ ion
- 2 NH₄⁺ ions (from (NH₄)₂SO₄)
- 2 SO₄²⁻ ions (one from each sulfate in the formula)

Now, we can summarize the ions:
- 1 Fe²⁺
- 2 NH₄⁺
- 2 SO₄²⁻

4. **Total Number of Ions**:
Now, we add the number of ions:
- 1 (Fe²⁺) + 2 (NH₄⁺) + 2 (SO₄²⁻) = 5 ions in total.

### Final Answer:
The total number of ions formed on dissolving one molecule of `FeSO₄(NH₄)₂SO₄·6H₂O` is **5**.

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