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 forms (c) acetamide.

Step 1: Understanding the Chemical Reaction

Ammonium acetate \((NH_4CH_3COO)\) is a compound that, on strong heating, undergoes decomposition. We must understand what happens at the molecular level during this reaction.

Step 2: Predicting the Decomposition Products

Heating ammonium acetate leads to the loss of water and rearrangement of atoms. The key to solving this problem is recognizing the rearrangement to form simpler molecules.

Step 3: Recognizing the Reaction Process

The decomposition of ammonium acetate involves the formation of acetamide (CH3CONH2) as one of its primary decomposition products. This is a result of an intramolecular reaction where the ammonium group and the acetate group recombine to lose water and form acetamide.

Step 4: Analyzing the Options

From the options given, (c) acetamide, matches the product formed during the decomposition of ammonium acetate. We can rule out the choices for urea (a), formamide (b), and methyl cyanide (d) as they are formed under different conditions or from different compounds.

Key Concepts

Understanding Chemical Reactions

A chemical reaction occurs when substances, called reactants, undergo a transformation to form new substances, known as products. In the context of ammonium acetate decomposition, the focus is on how heat induces the breakdown and reformation of molecular structures. In a typical chemical reaction:

• The bonds between atoms in reactants are broken.
• New bonds are formed to create the products.

When ammonium acetate \(NH_4CH_3COO\) is strongly heated, it undergoes a chemical reaction where its molecular structure rearranges, leading to the formation of different products. This involves the breaking of some bonds and the formation of new ones, which is the essence of most chemical reactions. This reaction's outcome is determined by the nature of the reactants and the conditions under which they react, such as temperature and pressure. In our specific scenario, heating causes a rearrangement that favors the formation of acetamide.

Identifying Decomposition Products

Decomposition products refer to the new substances formed when a compound breaks down. When ammonium acetate is heated, it decomposes. This process implies breaking down the compound into its component atoms or smaller molecules. In this decomposition:

• Water molecules are lost, indicating a dehydration reaction.
• Internal atoms rearrange to form the primary decomposition product, acetamide (\(CH_3CONH_2\)).

Understanding this rearrangement is crucial as it highlights how specific elements in a molecule can shift to produce entirely new compounds. This knowledge is not only applicable to ammonium acetate but is a widespread concept in chemistry essential for predicting the behavior of similar compounds under various conditions. Thus, the decomposition of ammonium acetate emphasizes the product's formation via internal molecular transformations.

Exploring Intramolecular Reactions

Intramolecular reactions occur within a single molecule when components of the molecule react with each other. For ammonium acetate, this means the components that make up the molecule interact internally.

• The ammonium group (\(NH_4^+\)) interacts with the acetate group (\(CH_3COO^-\)).
• This interaction results in bond rearrangement that eventually leads to the loss of water, forming acetamide.

These types of reactions are vital as they illustrate how molecules can undergo significant structural changes without the need for an external reactant. In the case of ammonium acetate, the intramolecular reaction forms a stable product (acetamide) by utilizing the existing components within the molecule. Such reactions are essential in organic chemistry as they explain many pathways through which molecules can convert from one form to another, facilitating the synthesis of complex compounds.