Which of the following statements is true is case of alkyl halides ?

Options

A. They are polar in nature
B. They can form hydrogen bonds
C. They are highly soluble in water
D. They undergo addition reactions

Answer

To solve the question regarding which statement is true in the case of alkyl halides, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Understanding Alkyl Halides:**
- Alkyl halides, also known as haloalkanes, are compounds where one or more hydrogen atoms in an alkane are replaced by halogen atoms (such as fluorine, chlorine, bromine, or iodine).
- General formula: R-X, where R is an alkyl group and X is a halogen.

2. **Evaluating Statement 1: "They are polar in nature."**
- Alkyl halides are indeed polar due to the electronegativity difference between the carbon atom and the halogen atom.
- The halogen atom is more electronegative than carbon, which causes the shared electrons in the carbon-halogen bond to be pulled closer to the halogen, creating a dipole moment.
- This results in a partial negative charge on the halogen and a partial positive charge on the carbon, confirming that alkyl halides are polar.
- **Conclusion:** This statement is true.

3. **Evaluating Statement 2: "They can form hydrogen bonds."**
- Hydrogen bonds are strong intermolecular forces that occur when hydrogen is bonded to highly electronegative atoms like oxygen, nitrogen, or fluorine.
- Alkyl halides do not have the ability to form hydrogen bonds with water because the interactions between alkyl halides and water molecules are weaker than the hydrogen bonding that occurs between water molecules themselves.
- **Conclusion:** This statement is false.

4. **Evaluating Statement 3: "They are highly soluble in water."**
- Alkyl halides are generally not soluble in water. They are only slightly soluble due to the weak interactions between alkyl halides and water.
- The energy released when alkyl halides dissolve in water is not sufficient to overcome the hydrogen bonds between water molecules.
- **Conclusion:** This statement is false.

5. **Evaluating Statement 4: "They undergo addition reactions."**
- Alkyl halides primarily undergo substitution and elimination reactions rather than addition reactions.
- Addition reactions typically occur with alkenes and alkynes, where pi bonds are broken to form new sigma bonds.
- **Conclusion:** This statement is false.

### Final Answer:
The only true statement regarding alkyl halides is: **"They are polar in nature."**

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