To determine in which compound oxygen does not show a -2 oxidation state, we will analyze the oxidation states of oxygen in the given compounds: H2O, CO2, F2O, and OCl.
### Step-by-Step Solution:
1. **Identify the Compounds**: The compounds given are H2O (water), CO2 (carbon dioxide), F2O (difluorine monoxide), and OCl (hypochlorous acid).
2. **Calculate the Oxidation State of Oxygen in H2O**:
- In H2O, let the oxidation state of oxygen be \( x \).
- The oxidation state of hydrogen (H) is +1.
- The equation can be set up as follows:
\[
2(+1) + x = 0
\]
- Solving for \( x \):
\[
2 + x = 0 \implies x = -2
\]
- Thus, in H2O, oxygen has an oxidation state of -2.
3. **Calculate the Oxidation State of Oxygen in CO2**:
- In CO2, let the oxidation state of oxygen be \( x \).
- The oxidation state of carbon (C) is +4 (since there are two oxygen atoms).
- The equation can be set up as follows:
\[
+4 + 2x = 0
\]
- Solving for \( x \):
\[
4 + 2x = 0 \implies 2x = -4 \implies x = -2
\]
- Thus, in CO2, oxygen also has an oxidation state of -2.
4. **Calculate the Oxidation State of Oxygen in F2O**:
- In F2O, let the oxidation state of oxygen be \( x \).
- The oxidation state of fluorine (F) is -1, and there are two fluorine atoms.
- The equation can be set up as follows:
\[
2(-1) + x = 0
\]
- Solving for \( x \):
\[
-2 + x = 0 \implies x = +2
\]
- Thus, in F2O, oxygen has an oxidation state of +2.
5. **Calculate the Oxidation State of Oxygen in OCl**:
- In OCl, let the oxidation state of oxygen be \( x \).
- The oxidation state of chlorine (Cl) is -1.
- The equation can be set up as follows:
\[
x + (-1) = 0
\]
- Solving for \( x \):
\[
x - 1 = 0 \implies x = +1
\]
- Thus, in OCl, oxygen has an oxidation state of +1.
6. **Conclusion**:
- From the calculations:
- H2O: -2
- CO2: -2
- F2O: +2
- OCl: +1
- Therefore, the compound in which oxygen does not show a -2 oxidation state is **F2O**.
### Final Answer:
**F2O (difluorine monoxide)** is the compound in which oxygen does not show a -2 oxidation state.
