Problem 155 - A Complete Resource Book in Chemistry for JEE Main

Question

Match the following Column-I (a) Oxygen (b) Sulphur (c) Nitrogen (d) Chlorine Column-II (p) Octa atomic (q) Diatomic (r) Paramagnetic (s) Diamagnetic

Step-by-Step Solution

Answer

Oxygen: (q)/(r), Sulphur: (p), Nitrogen: (q)/(s), Chlorine: (q)/(s)

Step 1: Analyze Elements in Column-I

Identify the characteristics of each element in Column-I: - Oxygen (O) - Sulphur (S) - Nitrogen (N) - Chlorine (Cl)

Step 2: Match Oxygen (a)

Oxygen molecules (O_2) are known to be diatomic and paramagnetic. Thus, the closest match would be: - (q) Diatomic - (r) Paramagnetic Match: (a) Oxygen → (q)/(r)

Step 3: Match Sulphur (b)

Sulphur typically exists in the form of S_8 molecules, which is an octa atomic arrangement. Therefore, the match is: - (p) Octa atomic Match: (b) Sulphur → (p)

Step 4: Match Nitrogen (c)

Nitrogen molecules (N_2) are diatomic and generally diamagnetic at room temperature. The possible matches are: - (q) Diatomic - (s) Diamagnetic Match: (c) Nitrogen → (q)/(s)

Step 5: Match Chlorine (d)

Chlorine naturally exists as diatomic molecules (Cl_2) and is typically diamagnetic. Thus, the possible matches are: - (q) Diatomic - (s) Diamagnetic Match: (d) Chlorine → (q)/(s)

Key Concepts

Diatomic Molecules

Atoms of some elements naturally pair up to form molecules with two atoms. These are called diatomic molecules. The composition consists of two atoms, either of the same or different chemical elements.
For instance, oxygen exists as the diatomic molecule \(O_2\), which is made up of two oxygen atoms bonded together. Other typical examples are nitrogen \(N_2\) and chlorine \(Cl_2\).

• Diatomic molecules are usually formed by covalent bonds.
• They possess characteristics based on the element; for example, oxygen \(O_2\) is known for being paramagnetic.

Understanding diatomic molecules helps explain how gases behave and why certain elements naturally form specific molecular arrangements.

Paramagnetism

Paramagnetism is a form of magnetism which occurs only in the presence of an externally applied magnetic field.
It results in the elements' ability to be weakly attracted to a magnetic field.
In the context of this exercise, oxygen \(O_2\) is a classic example of a paramagnetic diatomic molecule due to unpaired electrons in its molecular orbital.

• Paramagnetic substances have one or more unpaired electrons.
• This property is detected by its attraction into a magnetic field.

The degree of paramagnetism is usually quite weak compared to ferromagnetism, and it's important in understanding molecule behavior in various environments.

Diamagnetism

In contrast to paramagnetism, diamagnetism is a property that some materials exhibit in presence of an external magnetic field where they create a slight repulsion from the field.
Diamagnetic materials have all paired electrons, resulting in no permanent magnetic dipole moment.
Both nitrogen \(N_2\) and chlorine \(Cl_2\) are good examples of diatomic molecules that exhibit diamagnetism.

• Diamagnetism is a universal property of matter but often too weak to be noticed.
• It is seen in materials with complete electron pairing.

Understanding diamagnetism aids in predicting how molecules will interact with external magnetic fields.

Polyatomic Molecules

Polyatomic molecules consist of more than two atoms. These molecules contain multiple atoms, which could be either identical or different.
A well-known example of a polyatomic molecule is sulfur \(S_8\). It forms an eight-atom ring structure, which is distinct from simple binary diatomic molecules.

• Sulfur also demonstrates how varied atomic arrangement can occur leading to different properties.
• They often appear in complex forms, including chains and other geometric configurations.

Recognizing and understanding polyatomic molecules and their structures is essential for appreciating the diversity of chemical compounds found in nature.