Determine the formal charge on each oxygen atom in ozone

Answer

To determine the formal charge on each oxygen atom in ozone (O₃), we can follow these steps:

### Step 1: Draw the Lewis Structure of Ozone
Ozone consists of three oxygen atoms. The Lewis structure can be represented as follows:
```
O
//
O
\
O
```
In this structure, one oxygen atom is double bonded to the central oxygen atom, while the other oxygen atom is single bonded to the central oxygen atom.

### Step 2: Identify Valence Electrons
Each oxygen atom has 6 valence electrons. Therefore, for ozone, the total number of valence electrons is:
\[ 3 \text{ O} \times 6 \text{ valence electrons} = 18 \text{ valence electrons} \]

### Step 3: Calculate Formal Charge for Each Oxygen Atom
The formula for calculating formal charge (FC) is:
\[ \text{FC} = V - L - \frac{1}{2}S \]
where:
- \( V \) = number of valence electrons in the free atom
- \( L \) = number of lone pair electrons
- \( S \) = number of shared (bonding) electrons

#### Oxygen Atom 1 (Double Bonded)
- Valence electrons (V) = 6
- Lone pair electrons (L) = 4 (2 lone pairs)
- Shared electrons (S) = 4 (2 double bonds)

Calculating formal charge:
\[ \text{FC} = 6 - 4 - \frac{1}{2}(4) = 6 - 4 - 2 = 0 \]

#### Oxygen Atom 2 (Central Oxygen)
- Valence electrons (V) = 6
- Lone pair electrons (L) = 2 (1 lone pair)
- Shared electrons (S) = 6 (2 from the double bond and 2 from the single bond)

Calculating formal charge:
\[ \text{FC} = 6 - 2 - \frac{1}{2}(6) = 6 - 2 - 3 = +1 \]

#### Oxygen Atom 3 (Single Bonded)
- Valence electrons (V) = 6
- Lone pair electrons (L) = 6 (3 lone pairs)
- Shared electrons (S) = 2 (1 single bond)

Calculating formal charge:
\[ \text{FC} = 6 - 6 - \frac{1}{2}(2) = 6 - 6 - 1 = -1 \]

### Step 4: Summarize the Formal Charges
- Formal charge on Oxygen Atom 1 = 0
- Formal charge on Oxygen Atom 2 = +1
- Formal charge on Oxygen Atom 3 = -1

### Final Structure with Formal Charges
The formal charge distribution in ozone can be represented as:
```
O⁰
//
O⁺
\
O⁻
```