Problem 145 - A Complete Resource Book in Chemistry for JEE Main

Question

The end product (c) in this reaction, \(\mathrm{CH}_{3} \mathrm{COOH} \stackrel{\mathrm{CaCO}_{3}}{\longrightarrow} \mathrm{A} \stackrel{\text { Heat }}{\longrightarrow} \mathrm{B}\) \(\stackrel{\mathrm{NH}_{2} \mathrm{OH}}{\longrightarrow} \mathrm{C}\), is (a) Acetaldehyde oxime (b) Aceto oxime (c) Acetamide (d) Ethane nitrile

Step-by-Step Solution

Answer

(b) Aceto oxime

Step 1: Identify the first reaction outcome

The first reaction is \( \mathrm{CH}_{3} \mathrm{COOH} \stackrel{\mathrm{CaCO}_{3}}{\longrightarrow} \mathrm{A} \). Here, acetic acid (\( \mathrm{CH}_{3} \mathrm{COOH} \)) reacts with \( \mathrm{CaCO}_{3} \) to form calcium acetate \( (\mathrm{CH}_{3} \mathrm{COO})_2\mathrm{Ca} \). However, for simplicity, we can consider the formation of acetone (\( \mathrm{CH}_{3} \mathrm{COCH}_{3} \)), depending on decomposition.

Step 2: Analyze what happens when heated

The reaction \( \mathrm{A} \stackrel{\text{Heat}}{\longrightarrow} \mathrm{B} \) implies that acetone is pyrolyzed, potentially decomposing but remaining as acetone here due to general interpretation, possibly leading to compounds involving methyl and carbonyl groups.

Step 3: Reaction with NH2OH

Finally, \( \mathrm{B} \stackrel{\mathrm{NH}_2 \mathrm{OH}}{\longrightarrow} \mathrm{C} \) sees acetone reacting with hydroxylamine (\( \mathrm{NH}_2 \mathrm{OH} \)) to form acetone oxime, which is a ketoxime (\( \mathrm{C} \) is \( \mathrm{CH}_{3}-\mathrm{C}{=}\mathrm{NOH}-\mathrm{CH}_{3} \)).

Step 4: Determine the identity of product C

The product \( \mathrm{C} \) is a compound formed from the reaction of acetone with hydroxylamine and is acetone oxime, which is referred to as aceto oxime based on its structure.

Key Concepts

acetone

Acetone is one of the simplest forms of ketone, a vital compound in organic chemistry. It is often used as a solvent due to its ability to dissolve many substances.

Acetone (\( \text{CH}_3\text{COCH}_3 \)) is naturally produced in the body during fat metabolism. In an industrial setting, it is synthesized via the cumene process from propylene and benzene.

• It is a colorless liquid with a distinct, sweet odor.
• It evaporates rapidly and is highly flammable, making it significant in contexts requiring quick-drying substances.

In our particular exercise, acetone serves as a key intermediate product, transitioning from acetic acid to its oxime derivative. Its interaction with hydroxylamine leads to the formation of acetone oxime, highlighting its pivotal role in ketoxime synthesis.

While it may seem simple, acetone's versatility lies in multiple applications, ranging from a cleaning agent to a laboratory essential for chemical reactions.

chemical reactions

Chemical reactions involve the transformation of substances through the breaking and forming of bonds. In organic chemistry, such reactions often are used to synthesize complex molecules from simpler ones.

In this exercise, we witness a series of chemical reactions:

• Reaction with calcium carbonate: Acetic acid (\( \text{CH}_3\text{COOH} \)) reacts with calcium carbonate (\( \text{CaCO}_3 \)) to form acetone.
• Reaction upon heating: The heating of acetone results in some pyrolysis but it remains acetone or easily reverts due to its stability.
• Reaction with hydroxylamine: Acetone reacts with hydroxylamine (\( \text{NH}_2\text{OH} \)) to produce acetone oxime.

The understanding of these reactions is critical. We observe the meticulous changes and transformations, showing how starting materials can be harnessed to yield specific end products.
The manipulation of chemical bonds, especially in organic molecules, allows chemists to explore new structures and functions, paving the way for innovation and discovery.

organic chemistry

Organic chemistry is the branch of chemistry focused on compounds that contain carbon. It is foundational for understanding the chemistry of living organisms and a plethora of synthetic materials.

In the realm of organic chemistry, the manipulation of carbon-based molecules is mainly concerned with transforming simple reactants into complex products. This is achieved through the diverse spectrum of reaction mechanisms that define organic transformations.

• These reactions often involve the making and breaking of carbon-carbon and carbon-heteroatom bonds.
• The focus extends to reaction predictability and selectivity to optimize desired product yields.

The exercise highlights a typical pathway in organic synthesis, where a sequence of reactions is carefully planned and executed. Here, the conversion of acetic acid to acetone and then into acetone oxime demonstrates the elegant complexity and precision inherent in organic chemistry.
Understanding these principles is crucial, not just in academic contexts, but in practical applications like pharmaceuticals, agriculture, and materials science where organic compounds play key roles.