Question

Given below are two statements: 
Statement I: Dimethyl ether is completely soluble in water. However, diethyl ether is soluble in water to a very small extent.
Statement II: Sodium metal can be used to dry diethyl ether and not ethyl alcohol.
In the light of the given statements, choose the correct answer from the options given below:

• A. Statement I is false but Statement II is true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Both Statement I and Statement II are true

Hint:

When using sodium metal to dry ethers, ensure that the solution is free of water. Sodium reacts with water to form sodium hydroxide and hydrogen gas.

Answer 1

The Correct Option is D

Step 1: Analyze Statement I
Dimethyl ether (\(CH_3OCH_3\)) is moderately soluble in water, but not completely. It does exhibit hydrogen bonding but due to the small size of the molecule, its solubility in water is limited. Diethyl ether (\(C_2H_5OC_2H_5\)) is only slightly soluble in water due to its larger hydrophobic ethyl groups. This statement is partially correct as diethyl ether is indeed soluble in water, but to a very small extent.
Thus, Statement I is true because it correctly describes the solubility of both ethers, although dimethyl ether’s solubility is greater than diethyl ether.
Step 2: Analyze Statement II
Sodium metal is used to dry diethyl ether because it reacts with any water present, forming sodium hydroxide and hydrogen gas.
Ethyl alcohol (ethanol), however, reacts with sodium metal, forming sodium ethoxide and hydrogen, and thus cannot be dried by sodium.
Thus, Statement II is true because sodium can dry diethyl ether but cannot be used for drying ethyl alcohol.

Answer 2

Statement-I is correct because both the given ethers (Di-ethyl ether and butan-1-ol) are soluble in water. This solubility is due to the ability of the molecules to form hydrogen bonds with water molecules. Di-ethyl ether and butan-1-ol are miscible to almost the same extent, with 7.5 gm and 9 gm dissolving per 100 ml of water, respectively. This occurs due to hydrogen bonding between the oxygen atom of the ether and the hydrogen atom of water molecules. Hence, the statement is correct due to the influence of hydrogen bonding in the solubility of these compounds in water.

Statement-II is also correct because sodium metal is not used with ethyl alcohol. In this case, hydrogen gas (H₂) is released when sodium reacts with ethyl alcohol, as sodium displaces the hydrogen atom from the alcohol. However, this reaction does not involve sodium directly with ethyl alcohol, as the reaction leads to the release of hydrogen gas. Therefore, the statement is correct because sodium does not react directly in the same manner as with other alcohols, and hydrogen gas is released instead.