Problem 83 - A Complete Resource Book in Chemistry for JEE Main

Question

On strong heating, ammonium acetate gives (a) urea (b) formamide (c) acetamide (d) methyl cyanide

Step-by-Step Solution

Answer

On strong heating, ammonium acetate gives acetamide (c).

Step 1: Analyze the compound

Ammonium acetate (NH4CH3COO) is an organic compound that can decompose into different products upon heating. We need to determine the decomposition pathway.

Step 2: Identify possible decomposition reactions

On heating, ammonium acetate can undergo a thermally-induced rearrangement reaction. It's paramount to consider the functional groups and possible intermolecular reactions.

Step 3: Determine the most likely reaction

The reaction that occurs upon strong heating of ammonium acetate is a rearrangement where the ammonium ion ext{NH}_4^+ decomposes, leading to the formation of acetamide (CH3CONH2).

Step 4: Verify with chemical knowledge

Based on standard organic chemistry, the likely transition involves intramolecular proton transfer, resulting in the formation of acetamide, a process supported by experimental data on such decompositions.

Key Concepts

Rearrangement Reactions

A rearrangement reaction is a type of chemical reaction where the structure of a molecule is rearranged to form a different molecule. In this process, atoms or groups of atoms shift from one position to another within the same molecule, resulting in a new molecular structure. This can lead to significant changes in the properties of the compound.

• Rearrangement reactions often occur under specific conditions such as heat or the presence of a catalyst.
• They play a crucial role in various biochemical and industrial processes, making them important subjects in chemistry.

In the context of ammonium acetate, when it is heated, a rearrangement reaction occurs, resulting in the formation of acetamide. This is an example of how rearrangement reactions can lead to new compounds with different chemical properties.

Ammonium Acetate Decomposition

Ammonium acetate ( ext{NH}_4 ext{CH}_3 ext{COO}) decomposes upon heating. This decomposition is a chemical change that results in simpler or different compounds from the original substance. The decomposition pathway of ammonium acetate is particularly interesting, as it showcases the transformation into acetamide (CH3CONH2) when heated.

• The decomposition reaction involves breaking the bonds within the ammonium acetate and rearranging its atoms.
• The process results in a shift from the ionic structure of ammonium acetate to the covalent structure of acetamide.

This transformation is vital in understanding not just theoretical chemistry but also practical applications where such rearrangements can be harnessed in synthetic processes.

Intramolecular Proton Transfer

Intramolecular proton transfer is a fundamental concept where a proton (H+) is transferred within a molecule, resulting in a change in the structure of that molecule. This process is key in many organic reactions, including those involving ammonium acetate.
In the decomposition of ammonium acetate, an intramolecular proton transfer occurs:

• This means the proton from the ammonium group ( ext{NH}_4^+) moves within the molecule to a nearby group, facilitating the rearrangement of atoms.
• Such a transfer often helps stabilize intermediates and promote the formation of a more stable product, which in this case, is acetamide.

Understanding intramolecular proton transfer aids in predicting the outcome of reactions and is crucial for the manipulation and control of chemical processes in research and industry.