Problem 46 - A Complete Resource Book in Chemistry for JEE Main

Question

The maximum number of carbon atoms arranged linearly in the molecule, \(\mathrm{CH}_{3}-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}=\mathrm{CH}_{2}\) are (a) 3 (b) 4 (c) 5 (d) 6

Step-by-Step Solution

Answer

The maximum number of carbon atoms in a linear chain is 5.

Step 1: Understanding the Problem

The molecule given is \( \mathrm{CH}_{3}-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}=\mathrm{CH}_{2} \). We need to determine the maximum number of carbon atoms that are connected in a single linear chain in this molecule.

Step 2: Identify the Chain

Analyzing the molecule structure, we can observe that all the carbon atoms are connected in a straight line: \(\mathrm{CH}_{3}-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}=\mathrm{CH}_{2}\).

Step 3: Count the Carbon Atoms

Count the carbon atoms that are directly bonded in a linear fashion within this structure. We have: \(1. \mathrm{CH}_3 (\text{Methyl group}) ->2. \mathrm{C} (Triple-bonded) ->3. \mathrm{C} (Triple-bonded) ->4. \mathrm{CH} (Double-bonded) ->5. \mathrm{CH}_2 (Double-bonded) \).This gives us a total of 5 carbon atoms arranged in a chain.

Step 4: Select the Correct Answer

Since the maximum number of carbon atoms arranged linearly is 5, the answer is option (c) 5.

Key Concepts

Organic Chemistry

Organic chemistry is a branch of chemistry that focuses on the study of carbon-based compounds. It plays a crucial role in understanding the structure, characteristics, and reactions of molecules containing carbon. Carbon is unique due to its capability to form stable bonds with other carbon atoms, leading to the diversity of organic molecules. Besides carbon, organic compounds often contain elements such as hydrogen, oxygen, nitrogen, sulfur, and phosphorus.

One of the fundamental concepts in organic chemistry is the ability of carbon to form chains and rings, leading to various structural forms. These structural forms include alkanes (single bonds), alkenes (double bonds), and alkynes (triple bonds), which are foundational in determining the properties and reactivity of organic molecules. Understanding these structures leads students to grasp the chemical behavior of organic compounds better.

• Organic molecules contain carbon atoms.
• Carbon can form single, double, and triple bonds.
• Structures include chains, rings, and branches.

Molecular Structure

Molecular structure refers to the arrangement of atoms within a molecule. In the context of organic chemistry, this often relates to how carbon atoms are bonded together, as well as how these atoms are connected to other elements like hydrogen.

The structure of a molecule affects its physical and chemical properties. For example, the linear arrangement of carbon atoms in a molecule can influence its boiling point, solubility, and reactivity. In linear carbon chains like the one in the given exercise, each carbon atom is connected end-to-end, making it straightforward to identify the longest continuous chain in a molecule.

Understanding molecular structure requires knowledge of different types of bonds:

• Single Bonds: Formed by sharing one pair of electrons.
• Double Bonds: Formed by sharing two pairs of electrons.
• Triple Bonds: Formed by sharing three pairs of electrons, as seen in alkynes.

This knowledge is critical in determining the connectivity and geometry of molecules.

Carbon Bonding

Carbon bonding is a key topic in organic chemistry. Carbon atoms can form four covalent bonds, allowing for a vast array of possible structures. This is due to carbon’s ability to hybridize its orbitals to form different types of bonds: sigma (\(\sigma\)) and pi (\(\pi\)) bonds.

Carbon’s versatility allows it to bond with many elements and to form chains, branching structures, and rings. In the given molecule, carbon forms both triple and double bonds:

• Triple Bonds: Made up of one sigma bond and two pi bonds, allowing for linear geometry.
• Double Bonds: Comprised of one sigma bond and one pi bond, allowing for a planar configuration.

Such bonding varieties explain the backbone of organic molecules, linking together long chains or rings of carbon. These structural diversities are crucial factors in determining the properties of organic compounds.

JEE Main Chemistry

In prepping for JEE Main Chemistry, understanding the concept of linear carbon chains is vital. This is part of the fundamental knowledge required to solve questions related to organic chemistry.

The JEE Main exam tests students' ability to apply concepts like molecular structure, carbon bonding, and functional groups in complex problem-solving scenarios. Familiarity with linear carbon chains enables students to predict the properties and reactivities of organic molecules.

To prepare effectively for JEE Main Chemistry:

• Understand and visualize organic structures.
• Practice counting linear carbon chains in various molecules.
• Learn about the properties influenced by different types of carbon bonds.

These strategies will help in tackling questions that require a deep understanding of organic chemistry and enhance problem-solving skills needed for the exam.