In which case the `sigma` bond pair and `pi` bond pair of electrons both are attracted in the same direction (towards same atom):

Options

A. `H_(2)C=CH-Cl`
B. `CH_(3)-CH_(2)-NH_(2)`
C. `H_(2)C=CH-CH=O`
D. `H_(2)C=CH-OCH_(3)`

Answer

To solve the question of in which case the sigma bond pair and pi bond pair of electrons are both attracted in the same direction towards the same atom, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Sigma and Pi Bonds**:
- Sigma (σ) bonds are formed by the head-on overlap of orbitals and are generally stronger.
- Pi (π) bonds are formed by the side-to-side overlap of p-orbitals and are generally weaker.
- Both types of bonds can have their electron density influenced by electronegative atoms.

2. **Analyzing Each Option**:
- **Option A: CH₂=PHCl**
- Chlorine (Cl) is electronegative and pulls electron density towards itself (negative inductive effect).
- The lone pairs on Cl can also interact, leading to opposite directions for sigma and pi bonds.
- **Conclusion**: Incorrect, as sigma and pi bonds are attracted in opposite directions.

- **Option B: CH₃CH₂NH₂**
- Nitrogen (N) is also electronegative and has a lone pair that can donate electrons (resonance).
- The electron-withdrawing effect of N causes opposite directions for sigma and pi bonds.
- **Conclusion**: Incorrect, as sigma and pi bonds are attracted in opposite directions.

- **Option C: CH₂=CH-CH=O**
- Oxygen (O) is electronegative and pulls electron density towards itself.
- The pi bond is attracted towards O, and the sigma bond also shifts in the same direction due to the resonance effect.
- **Conclusion**: Correct, as both sigma and pi bonds are attracted in the same direction towards oxygen.

- **Option D: CH₃CH=CH-O-CH₃**
- Similar to option C, oxygen has a lone pair that can donate electrons, leading to opposite directions for sigma and pi bonds.
- **Conclusion**: Incorrect, as sigma and pi bonds are attracted in opposite directions.

3. **Final Answer**:
- The only option where both the sigma bond pair and pi bond pair of electrons are attracted in the same direction is **Option C: CH₂=CH-CH=O**.