Problem 197 - A Complete Resource Book in Chemistry for JEE Main

Question

Picric acid is (a) O=[N+]([O-])c1cc([N+](=O)[O-])c(O)c([N+](=O)[O-])c1 (b) O=C(O)c1cccc([N+](=O)[O-])c1(c) O=C(O)c1cccc(O)c1 (d) Nc1cccc(C(=O)O)c1

Step-by-Step Solution

Answer

Option (a) is picric acid.

Step 1: Understanding Picric Acid

Picric acid is a chemical compound with the formula C6H3N3O7. It is a nitro derivative of phenol and is also known as 2,4,6-trinitrophenol.

Step 2: Analyze Option (a)

The SMILES for option (a) indicates a benzene ring with three nitro groups (NO2) and one hydroxyl group (OH), which corresponds to 2,4,6-trinitrophenol, also known as picric acid.

Step 3: Analyze Option (b)

The SMILES for option (b) shows a carboxylic acid group (COOH) attached to a benzene ring, along with one nitro group. This structure resembles nitrobenzoic acid, not picric acid.

Step 4: Analyze Option (c)

The SMILES for option (c) indicates a carboxylic acid group and a hydroxyl group attached to a benzene ring. This describes salicylic acid, not picric acid.

Step 5: Analyze Option (d)

The SMILES for option (d) shows an amine group (NH2) and a carboxylic acid group attached to a benzene ring, fitting the description of aminobenzoic acid, not picric acid.

Key Concepts

Chemical Structure Analysis

Chemical structure analysis is pivotal in understanding the composition and behavior of organic compounds like Picric Acid. By examining the chemical structure, you gain insight into how the atoms are arranged and how they interact with each other. For Picric Acid, the formula is C6H3N3O7, which reveals the presence of:

• Six carbon atoms forming a benzene ring, a common structural feature in organic chemistry.
• Three nitro groups (-NO2) and a hydroxyl group (-OH).

These components are critical as they determine the compound's chemical properties and reactivity. The nitro groups, for example, make Picric Acid explosive under certain conditions, whereas the hydroxyl group contributes to its acidity. By applying chemical structure analysis, you can predict these properties, making it a fundamental aspect of chemical studies.

Organic Chemistry

Organic chemistry focuses on the study of carbon-containing compounds like Picric Acid. This field explores how carbon bonds with elements like hydrogen, oxygen, and nitrogen to form complex structures. In Picric Acid, the carbon atoms form a stable benzene ring. This stability is a hallmark of aromatic compounds in organic chemistry.
The benzene ring in Picric Acid is substituted by nitro groups, which are typical functional groups in organic molecules. Understanding the role and interaction of such substituents is vital in predicting a compound's behavior and its potential applications.

• The presence of nitro groups in the benzene ring introduces electron-withdrawing effects, altering the ring's electronic nature.
• These groups make Picric Acid a strong acid compared to phenol, which is the parent compound.

Organic chemistry allows us to comprehend these interactions and predict how changes in structure affect chemical properties.

Functional Groups Identification

Identifying functional groups is crucial in classifying and understanding the reactivity of organic compounds. In Picric Acid, functional groups play a significant role in determining its chemical behavior. Here's what to look for:

• Nitro Groups (-NO2): These are strong electron-withdrawing groups, making the compound more acidic and affecting its stability and reactivity.
• Hydroxyl Group (-OH): This group is responsible for the acidic nature of Picric Acid, allowing it to donate protons to other compounds, which is a key feature in many chemical reactions.

Recognizing these functional groups in Picric Acid not only helps in classifying the compound but also in deducing possible interactions and reactions. Functional group identification is a fundamental skill in organic chemistry, providing a pathway to predict and understand the behavior of complex molecules.