Match List - I with List - II.

Choose the correct answer from the options given below:

(A)-(II), (B)-(III), (C)-(I), (D)-(IV)

The correct answer is option 4. (A)-(II), (B)-(III), (C)-(I), (D)-(IV).

Let us break down each pair of compounds and their corresponding tests or reagents to fully explain the rationale behind the correct matches.

(A) Ethanol and Diethyl ether : (II) Sodium metal

Ethanol (C₂H₅OH) reacts with sodium metal to release hydrogen gas:

\(2C_2H_5OH + 2Na \longrightarrow 2C_2H_5ONa + H_2 \uparrow \)

This is a common test for alcohols, where the hydrogen gas is released, indicating the presence of an alcohol group. Diethyl ether does not react with sodium metal in the same way.

Therefore, Ethanol reacts with Sodium metal. Diethyl ether is not the focus here because this pairing is testing the ethanol component.

Thus, (A) Ethanol and Diethyl ether matches with (II) Sodium metal.

(B) Methanol and Ethanol(III) Iodoform test

The Iodoform test identifies compounds that contain a methyl group attached to a carbonyl group \(-CH_3-C(OH)-\). Ethanol (\(CH_3CH_2OH\)) gives a positive iodoform test:

\(CH_3CH_2OH + 4I_2 + 6NaOH \longrightarrow \underset{\text{yellow ppt.}}{CHI_3}  + HCOONa + 5NaI + 5H_2O \)

This test produces a yellow precipitate of iodoform \(CHI_3\), confirming the presence of the \(-CH_3-C(OH)-\) group in ethanol.

Methanol (\(CH_3OH\)) does not give a positive iodoform test since it lacks the necessary group structure.

Thus, (B) Methanol and Ethanol matches with (III) Iodoform test.

(C) n-Butyl alcohol and tert. Butyl alcohol(I) Lucas reagent

Lucas reagent (a mixture of ZnCl₂ in concentrated HCl) is used to classify alcohols based on their reactivity:

Primary alcohols (like n-Butyl alcohol) react very slowly or not at all.

Secondary alcohols react moderately.

Tertiary alcohols (like tert-Butyl alcohol) react immediately, forming a cloudy solution due to the formation of an insoluble alkyl chloride.

The difference in reaction rates helps distinguish between alcohol types. In this case, tert-Butyl alcohol, a tertiary alcohol, reacts quickly, while n-Butyl alcohol, a primary alcohol, reacts very slowly.

Thus, (C) n-Butyl alcohol and tert-Butyl alcohol match with (I) Lucas reagent.

(D) Phenol and Cyclohexanol(IV) Ferric Chloride

The Ferric chloride test is used to detect phenols. When phenol reacts with ferric chloride \((FeCl_3)\), it forms a complex that gives a characteristic violet, purple, or blue-green color.

Cyclohexanol does not give a positive ferric chloride test because it lacks the phenolic \(-OH\) group directly attached to an aromatic ring.

Thus, (D) Phenol and Cyclohexanol match with (IV) Ferric chloride test.

So, the correct answer is option (4): (A)-(II), (B)-(III), (C)-(I), (D)-(IV).