Question

Which of the following ethers is gaseous at room temperature ?

• A. 1 - Methoxypropane
• B. 1 - Ethoxypropane
• C. Methoxyethane
• D. Ethoxyethane

Hint:

Fewer carbon atoms means a smaller molecular mass and a lower boiling point. Pick the smallest ether.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Ethers have no hydrogen bonding between their own molecules, so their boiling points depend mainly on molecular mass. A small ether has a boiling point close to or below room temperature and exists as a gas.

Step 2: Key Formula or Approach:
Count the carbon atoms of each ether. Fewer carbons means a lower molecular mass and a lower boiling point.

Step 3: Detailed Explanation:
1-Methoxypropane, \(\text{CH}_3\text{OCH}_2\text{CH}_2\text{CH}_3\), has 4 carbons and boils at about 39 degrees C, so it is a liquid.
1-Ethoxypropane has 5 carbons and boils at about 64 degrees C, so it is a liquid.
Ethoxyethane (diethyl ether) has 4 carbons and boils at about 35 degrees C, so it is a volatile liquid.
Methoxyethane, \(\text{CH}_3\text{OCH}_2\text{CH}_3\), has only 3 carbons and a molar mass of 60 g/mol. It boils at about 7 degrees C, which is below room temperature, so it is a gas.

Final Answer:
Only methoxyethane boils below room temperature, so it is the gaseous ether. This is option (C). \[ \boxed{\text{Methoxyethane (C)}} \]