Question

Identify the compound having lowest boiling point.

• A. \(\text{H}_{2}\text{O}\)
• B. \(\text{CH}_{2}(\text{OH})\text{-CH}_{2}(\text{OH})\)
• C. \(\text{CH}_{3}-\text{O}-\text{C}_{2}\text{H}_{5}\)
• D. \(\text{C}_{3}\text{H}_{7}-\text{OH}\)

Hint:

Compounds that form intermolecular hydrogen bonds boil at higher temperatures. Look for the one that cannot.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
Hydrogen bonding between molecules raises the boiling point sharply.

Step 2: Check Each Compound
\(\text{H}_2\text{O}\), ethylene glycol and propan-1-ol all contain O-H groups and form hydrogen bonds.

Step 3: Ether
\(\text{CH}_3\text{-O-C}_2\text{H}_5\) has no O-H bond, so it has only weak dipole-dipole and dispersion forces.

Final Answer:
The ether \(\text{CH}_3\text{-O-C}_2\text{H}_5\) has the lowest boiling point. \[ \boxed{\text{(C) }\text{CH}_{3}-\text{O}-\text{C}_{2}\text{H}_{5}} \]