Read the passage carefully and answer the Questions.
Ethers with the general formula $C_nH_{2n+2}O$ and functional group C-O-C may be divided as symmetrical and unsymmetrical. Lower symmetrical ether may be obtained by the dehydration of alcohols at low temeratures in the presence of protic acids, such as $H_2SO_4$ and $H_3PO_4$ wheras at high temperature intramolecular dehydration takes place. Formation of ether from primary alcohols is also accompanied by the formation of small amount of alkenes. Due to the stearic hinderance, secondary and tertiary alcohols undergo elimination reaction rather than substitution reaction yielding alkene as major product. Ethers can also be obtained by heating alkyl halides with sodium or potassium alkoxides. Substituted Ethers (secondary & tertiary) can also be prepared using this method. If primary halides are replaced with secondary and tertiary halides, alkenes are the major products.
The compound with the lowest boiling point is
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Ethers
For compounds of comparable molecular mass, the boiling points depend on the strength of intermolecular forces:
- Alcohols → Strong hydrogen bonding → Highest boiling point
- Aldehydes & Ketones → Dipole–dipole interactions → Moderate boiling points
- Ethers → No hydrogen bonding (only weak dipole interactions) → Lowest boiling point
Order of boiling points:
$\text{Alcohols} > \text{Aldehydes/Ketones} > \text{Ethers}$