In the electronic structure of `H_2SO_4`, the total number of unshared electrons is

Options

A. 20
B. 16
C. 12
D. 8

Answer

To determine the total number of unshared electrons in the electronic structure of sulfuric acid (H₂SO₄), we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Atoms in H₂SO₄**:
- H₂SO₄ consists of 2 hydrogen (H) atoms, 1 sulfur (S) atom, and 4 oxygen (O) atoms.

2. **Determine the Valence Electrons**:
- Hydrogen (H) has 1 valence electron. Since there are 2 hydrogen atoms, they contribute a total of 2 electrons.
- Sulfur (S) has 6 valence electrons.
- Each oxygen (O) has 6 valence electrons. With 4 oxygen atoms, they contribute a total of 24 electrons (4 × 6).

3. **Calculate Total Valence Electrons**:
- Total valence electrons = Electrons from H + Electrons from S + Electrons from O
- Total = 2 (from H) + 6 (from S) + 24 (from O) = 32 valence electrons.

4. **Draw the Lewis Structure of H₂SO₄**:
- In the Lewis structure, sulfur is the central atom. It forms double bonds with two of the oxygen atoms and single bonds with the other two oxygen atoms, which are each bonded to a hydrogen atom.

5. **Identify Shared and Unshared Electrons**:
- In the structure:
- Each double bond (S=O) consists of 4 shared electrons (2 pairs).
- Each single bond (S-O) consists of 2 shared electrons (1 pair).
- The oxygen atoms that are bonded to hydrogen each have 2 lone pair electrons (4 unshared electrons) because they have 6 valence electrons, and 2 are used in bonding with hydrogen.

6. **Count Unshared Electrons**:
- For each of the 4 oxygen atoms:
- 2 oxygen atoms (with double bonds) have 4 unshared electrons each (2 lone pairs).
- 2 oxygen atoms (with single bonds) also have 4 unshared electrons each (2 lone pairs).
- Therefore, total unshared electrons = 4 (from O with double bonds) + 4 (from O with single bonds) + 4 (from O with single bonds) + 4 (from O with double bonds) = 16 unshared electrons.

7. **Conclusion**:
- The total number of unshared electrons in H₂SO₄ is 16.

### Final Answer:
The total number of unshared electrons in H₂SO₄ is **16**.