Oxygen exhibits least oxidation state in

Options

A. `OF_(2)`
B. `KO_(2)`
C. `H_(2)O`
D. `H_(2)O_(2)`

Answer

To determine the least oxidation state of oxygen in the given compounds, we will analyze each compound one by one and calculate the oxidation state of oxygen.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds we are considering are:
- \( \text{OF}_2 \)
- \( \text{K}_2\text{O} \)
- \( \text{H}_2\text{O} \)
- \( \text{H}_2\text{O}_2 \)

2. **Calculate Oxidation State in \( \text{OF}_2 \)**:
- Fluorine (F) is more electronegative than oxygen (O) and has an oxidation state of -1.
- Since there are two fluorine atoms, the total contribution from fluorine is \( 2 \times (-1) = -2 \).
- To maintain neutrality, the oxidation state of oxygen must be \( +2 \).
- **Oxidation state of O in \( \text{OF}_2 \) = +2**.

3. **Calculate Oxidation State in \( \text{K}_2\text{O} \)**:
- Potassium (K) is an alkali metal and has an oxidation state of +1.
- There are two potassium atoms, contributing \( 2 \times (+1) = +2 \).
- To maintain neutrality, the oxidation state of oxygen must be \( -2 \).
- **Oxidation state of O in \( \text{K}_2\text{O} \) = -2**.

4. **Calculate Oxidation State in \( \text{H}_2\text{O} \)**:
- Hydrogen (H) has an oxidation state of +1.
- There are two hydrogen atoms, contributing \( 2 \times (+1) = +2 \).
- To maintain neutrality, the oxidation state of oxygen must be \( -2 \).
- **Oxidation state of O in \( \text{H}_2\text{O} \) = -2**.

5. **Calculate Oxidation State in \( \text{H}_2\text{O}_2 \)**:
- Each hydrogen atom has an oxidation state of +1.
- There are two hydrogen atoms, contributing \( 2 \times (+1) = +2 \).
- Let the oxidation state of oxygen be \( x \). Since there are two oxygen atoms, the equation becomes:
\[ 2 \times x + 2 = 0 \implies 2x = -2 \implies x = -1 \]
- **Oxidation state of O in \( \text{H}_2\text{O}_2 \) = -1**.

6. **Compare the Oxidation States**:
- \( \text{OF}_2 \): +2
- \( \text{K}_2\text{O} \): -2
- \( \text{H}_2\text{O} \): -2
- \( \text{H}_2\text{O}_2 \): -1

7. **Conclusion**:
- The least oxidation state of oxygen is found in \( \text{K}_2\text{O} \) and \( \text{H}_2\text{O} \), both having an oxidation state of -2. However, since the question asks for the least oxidation state, we can conclude that the least oxidation state of oxygen is **-2**.

### Final Answer:
Oxygen exhibits the least oxidation state in \( \text{K}_2\text{O} \) and \( \text{H}_2\text{O} \) (both -2).