Correct order of boiling points among following is ` CH_3(CH_2)_3CH_3 " " C_2H_5OC_2H_5 ," " CH_3 (CH_2)_3OH `

Options

A. `X lt Y lt Z `
B. ` Y gt Y lt Z `
C. ` Z lt X lt Y`
D. ` Z gt X lt X `

Answer

To determine the correct order of boiling points among the compounds CH₃(CH₂)₃CH₃ (alkane), C₂H₅OC₂H₅ (ether), and CH₃(CH₂)₃OH (alcohol), we can analyze the factors that affect boiling points.

### Step-by-Step Solution:

1. **Identify the Compounds**:
- X = CH₃(CH₂)₃CH₃ (n-pentane, an alkane)
- Y = C₂H₅OC₂H₅ (diethyl ether)
- Z = CH₃(CH₂)₃OH (1-pentanol, an alcohol)

2. **Consider the Functional Groups**:
- Alkane (X) - does not have any functional groups capable of hydrogen bonding.
- Ether (Y) - has an ether functional group, which can engage in some dipole-dipole interactions but no hydrogen bonding.
- Alcohol (Z) - has a hydroxyl (-OH) group, which allows for strong hydrogen bonding.

3. **Evaluate Hydrogen Bonding**:
- Alcohols can form strong intermolecular hydrogen bonds, which significantly increase boiling points.
- Ethers can engage in weaker dipole-dipole interactions but do not form hydrogen bonds.
- Alkanes have only weak Van der Waals forces.

4. **Analyze the Boiling Points**:
- Since Z (the alcohol) can form hydrogen bonds, it will have the highest boiling point.
- Between X (the alkane) and Y (the ether), ethers generally have higher boiling points than alkanes due to stronger dipole interactions, even though both lack hydrogen bonding.
- Therefore, the order of boiling points from lowest to highest is:
- X (alkane) < Y (ether) < Z (alcohol)

5. **Conclusion**:
- The correct order of boiling points is:
- CH₃(CH₂)₃CH₃ < C₂H₅OC₂H₅ < CH₃(CH₂)₃OH

### Final Answer:
The correct order of boiling points is:
**CH₃(CH₂)₃CH₃ < C₂H₅OC₂H₅ < CH₃(CH₂)₃OH**