Functional Groups

To solve this problem, we need to identify the suitable reagent for the given conversion.

1. Understanding the Reaction:
The reaction involves the oxidation of a compound with an alkene group (CH₃-CH=CH-CH₂-COCH₃). The product shows a carboxylic acid group (-COOH) on the terminal carbon. This suggests that the compound undergoes oxidation at the position of the alkene group (double bond), converting it to a carboxyl group.

2. Analyzing the Reagents:
Let's evaluate the possible reagents that could effect this transformation:

• Option (A) "Tollen's reagent": Tollen's reagent, which contains silver(I) ions (Ag⁺), is typically used to oxidize aldehydes to carboxylic acids, but it does not oxidize alkenes. Thus, this reagent is not suitable for this transformation.
• Option (B) "Benzoyl peroxide": Benzoyl peroxide is a radical initiator and is commonly used in the polymerization of alkenes. It can also initiate the formation of alkyl radicals, but it does not directly oxidize alkenes to carboxylic acids. This is not the correct choice for this conversion.
• Option (C) "I₂ and NaOH solution with subsequent acidification": This is a typical reaction for the oxidative cleavage of alkenes. The iodine (I₂) and NaOH solution will cleave the double bond of the alkene, and after acidification, a carboxylic acid is formed. This is a suitable reagent for the transformation described in the problem.
• Option (D) "Sn and NaOH solution": This combination is typically used for the reduction of carbonyl groups (e.g., in the reduction of aldehydes and ketones), not for the oxidation of alkenes. Thus, it is not suitable for this reaction.

Final Answer:
The most suitable reagent for this conversion is (C) "I₂ and NaOH solution with subsequent acidification," as it is used for the oxidative cleavage of alkenes to form carboxylic acids.

To solve this problem, we need to determine the nature of compounds A, B, and C based on the reactions described.

1. Analyzing the Reactions:
The given reactions involve a series of steps that convert a starting compound into acetaldehyde, and we need to identify the starting compounds (A, B, and C) based on these reactions.

Step 1: Reaction of A with :
This reaction suggests that compound A undergoes an acid-catalyzed hydration. Typically, alkenes undergo acid-catalyzed hydration to form alcohols. Thus, compound A is most likely an alkene. Given the final product is acetaldehyde, A must be ethene (C₂H₄), which on hydration forms ethanol (CH₃CH₂OH).

Step 2: Reaction of B with PCC (Pyridinium chlorochromate):
PCC is a mild oxidizing agent that selectively oxidizes primary alcohols to aldehydes without further oxidation to carboxylic acids. The fact that B gives acetaldehyde after reaction with PCC suggests that B is ethanol (CH₃CH₂OH), which is oxidized to acetaldehyde (CH₃CHO) by PCC.

Step 3: Reaction of C with SnCl₂/HCl and :
In this step, the reaction of C with SnCl₂/HCl suggests a reduction process, typically converting a nitrile group (-C≡N) to an amine group (-CH₂NH₂). The subsequent reaction with water leads to the formation of ethanol. Hence, compound C must be ethanenitrile (CH₃CN), which is reduced to ethanol (CH₃CH₂OH) using SnCl₂/HCl.

2. Identifying A, B, and C:
Based on the above analysis: - Compound A is ethene (C₂H₄), which forms ethanol (CH₃CH₂OH) on hydration. - Compound B is ethanol (CH₃CH₂OH), which is oxidized to acetaldehyde (CH₃CHO) by PCC. - Compound C is ethanenitrile (CH₃CN), which is reduced to ethanol (CH₃CH₂OH) by SnCl₂/HCl.

Final Answer:
The correct answer is (C) "ethanol, ethane nitrile and ethyne".

We can deduce the structure of compound 'A' from the given reactions and properties:

1. Compound 'A' is insoluble in NaHCO₃ solution, which suggests that it is not an acid, so it is not a carboxylic acid.
2. Compound 'A' dissolves in NaOH, which indicates that it is an alcohol (phenol or an alcohol). Since phenols are generally soluble in NaOH and alcohols are also soluble, we must further investigate.
3. Compound 'A' gives a characteristic colour with neutral FeCl₃ solution, which is a test for phenols. This reaction forms a coloured complex with phenolic compounds, indicating that 'A' is likely a phenol or an alcohol that can react in this way.
4. Compound 'A' reacts with Bromine water to form a compound B with the formula C₇H₅OBr, which suggests that 'A' undergoes bromination, typical of alcohols (especially phenols) and the resulting product is a bromo derivative. 

Based on these reactions, the correct compound 'A' is phenol (C₆H₅OH), and it undergoes bromination in the presence of bromine water to form a bromo derivative.

The correct answer is (B) : .

The carbylamine reaction, also known as the isocyanide test, is a chemical test used for the detection of primary amines. In this reaction, a primary amine reacts with chloroform in the presence of a base (typically potassium hydroxide) to form an isocyanide.

The resulting foul-smelling product formed in the carbylamine test is an:

Isocyanide (also known as a carbylamine)

Therefore, among the options provided, the correct representation of the product would be:

It is important to note that isocyanides are highly toxic compounds with an intensely unpleasant odor, which is why the carbylamine test is easily recognizable. Thus, the foul smelling product is: Option 1

To identify A, B, and C, let's break down the reaction steps:

Starting compound: The initial compound is CH₃CH₂Br (ethyl bromide), which is undergoing the following reactions.

Step 1: Reaction with KCN (alc):

The reaction with KCN in alcohol will cause a nucleophilic substitution reaction, where the bromine is replaced by a cyanide (CN) group. This gives the product CH₃CH₂CN (ethyl cyanide or propionitrile).

Therefore, A = CH₃CH₂CN.

Step 2: Reaction with LiAlH₄:

The reaction of nitriles with LiAlH₄ (Lithium aluminium hydride) reduces the nitrile group (CN) to an amine group (NH₂).

Therefore, B = CH₃CH₂CH₂NH₂ (ethylamine).

Step 3: Reaction with HNO₂ (Nitrous acid) at 0°C:

The reaction of amines with nitrous acid (HNO₂) at low temperatures leads to diazotization of the amine group and its subsequent replacement by a hydroxyl group. This converts the amine to an alcohol.

Therefore, C = CH₃CH₂CH₂OH (ethanol).

Final Answer:

A = CH₃CH₂CN (ethyl cyanide)

B = CH₃CH₂CH₂NH₂ (ethylamine)

C = CH₃CH₂CH₂OH (ethanol)

Option 1: CH₃CH₂CN, CH₃CH₂CH₂NH₂, CH₃CH₂CH₂OH is the correct answer.