In all oxides, peroxides and superoxides, the oxidation sate of alkali metals is

Options

A. `+1 and -1`
B. `+1 and +2`
C. `+1` only
D. `+1,-1 and +2`

Answer

To determine the oxidation state of alkali metals in oxides, peroxides, and superoxides, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Oxidation States**:
- In chemistry, the oxidation state (or oxidation number) indicates the degree of oxidation of an atom in a compound.

2. **Oxidation State of Oxygen**:
- In oxides, the oxidation state of oxygen is typically -2.
- In peroxides, the oxidation state of oxygen is -1.
- In superoxides, the oxidation state of oxygen is -1/2.

3. **Oxides of Alkali Metals**:
- The general formula for alkali metal oxides is \( M_2O \).
- Let the oxidation state of the alkali metal \( M \) be \( x \).
- The equation can be set up as follows:
\[ 2x + (-2) = 0 \]
- Solving for \( x \):
\[ 2x - 2 = 0 \implies 2x = 2 \implies x = +1 \]

4. **Superoxides of Alkali Metals**:
- The general formula for alkali metal superoxides is \( MO_2 \).
- Again, let the oxidation state of the alkali metal \( M \) be \( x \).
- The equation can be set up as follows:
\[ x + 2 \left(-\frac{1}{2}\right) = 0 \]
- Solving for \( x \):
\[ x - 1 = 0 \implies x = +1 \]

5. **Peroxides of Alkali Metals**:
- The general formula for alkali metal peroxides is \( M_2O_2 \).
- Let the oxidation state of the alkali metal \( M \) be \( x \).
- The equation can be set up as follows:
\[ 2x + 2(-1) = 0 \]
- Solving for \( x \):
\[ 2x - 2 = 0 \implies 2x = 2 \implies x = +1 \]

6. **Conclusion**:
- In all cases (oxides, peroxides, and superoxides), the oxidation state of alkali metals is consistently +1.

### Final Answer:
The oxidation state of alkali metals in oxides, peroxides, and superoxides is **+1**.