Which of the following is correct?

Options

A.
B.
C. `"Stability" prop "bond order" prop "bond length" prop "bond enthalpy"`
D. `"Stability" prop "bond order" prop "bond enthalpy" prop 1/"bond length"`

Answer

To solve the question regarding the relationships between bond order, bond length, bond enthalpy, and stability, we can break it down step by step.

### Step-by-Step Solution:

1. **Understanding Bond Order**:
- Bond order is defined as the number of bonding electrons minus the number of anti-bonding electrons divided by two. A higher bond order indicates a stronger bond.
- **Hint**: Remember that bond order reflects the strength of a bond.

2. **Relationship Between Bond Order and Stability**:
- A higher bond order means more bonding electrons are present compared to anti-bonding electrons, which leads to increased stability of the molecule.
- **Hint**: Think about how more bonding electrons contribute to a stronger attraction between atoms.

3. **Understanding Bond Length**:
- Bond length is the distance between the nuclei of two bonded atoms. Generally, as bond order increases, bond length decreases because the atoms are pulled closer together.
- **Hint**: Visualize how stronger bonds (higher bond order) pull atoms closer, resulting in shorter bond lengths.

4. **Relationship Between Stability and Bond Length**:
- As bond length increases, stability decreases. This is because longer bonds are generally weaker and more susceptible to breaking.
- **Hint**: Consider how a longer bond might allow for more movement and less stability.

5. **Understanding Bond Enthalpy**:
- Bond enthalpy is the amount of energy required to break a bond. A higher bond enthalpy indicates a stronger bond, which correlates with higher stability.
- **Hint**: Recall that more energy is needed to break stronger bonds.

6. **Relationship Between Bond Enthalpy and Stability**:
- There is a direct relationship: as bond enthalpy increases, stability also increases.
- **Hint**: Stronger bonds (higher enthalpy) mean that the molecule is more stable.

7. **Summarizing Relationships**:
- Stability is directly proportional to bond order and bond enthalpy.
- Stability is inversely proportional to bond length.
- **Hint**: Create a simple chart to visualize these relationships.

8. **Evaluating Options**:
- Now, we can evaluate the provided options based on our established relationships:
- **Option 1**: Incorrect because it states bond enthalpy is inversely proportional to stability.
- **Option 2**: Incorrect because it misrepresents the relationship between bond order and stability.
- **Option 3**: Incorrect as it incorrectly states that bond order is directly proportional to bond length.
- **Option 4**: Correct as it accurately describes the relationships: stability is directly proportional to bond order and bond enthalpy, and inversely proportional to bond length.

### Final Answer:
The correct option is **Option 4**.