Problem 35 - A Complete Resource Book in Chemistry for JEE Main

Question

The vapour density of ozone is (a) 24 (b) 16 (c) 48 (d) 72

Step-by-Step Solution

Answer

The vapour density of ozone is 24.

Step 1: Determine Molar Mass of Ozone

The chemical formula for ozone is \(O_3\). Each oxygen atom has an atomic mass of 16 g/mol. Therefore, the molar mass of ozone is calculated as follows: \(3 \times 16 = 48 \text{ g/mol.}\) Hence, the molar mass of ozone is 48 g/mol.

Step 2: Understand Vapour Density Formula

Vapour density is defined as half of the molar mass of a substance. Mathematically, it is expressed as: \(\text{Vapour Density} = \frac{\text{Molar Mass}}{2}.\)

Step 3: Calculate Vapour Density of Ozone

Using the formula \(\text{Vapour Density} = \frac{\text{Molar Mass}}{2}\), substitute the molar mass of ozone: \(\frac{48}{2} = 24.\) Therefore, the vapour density of ozone is 24.

Key Concepts

Molar Mass Calculation

Molar mass is a fundamental concept in chemistry, essential for understanding the mass of molecules and compounds. Let's focus on how to calculate it using the example of ozone. The molar mass of a compound is determined by summing up the atomic masses of all atoms in the molecule. For ozone, which has the chemical formula \(O_3\), we need to account for three oxygen atoms. Here is how you calculate it:

• Each oxygen atom has an atomic mass of 16 g/mol.
• In ozone, there are three oxygen atoms.
• Therefore, the calculation is \(3 \times 16 = 48 \text{ g/mol}\).

The total molar mass of ozone is 48 grams per mole. Remember, understanding how to find the molar mass helps you analyze chemical reactions and predict how different substances will interact.

Ozone

Ozone is a simple yet fascinating molecule widely known for its role in the Earth's atmosphere. Chemically, it is represented as \(O_3\). Unlike the typical diatomic oxygen molecule \(O_2\) that we breathe, ozone contains one extra oxygen atom, giving it unique properties.Here are some intriguing facts:

• Protective Layer: Ozone forms a protective layer in the Earth's stratosphere, absorbing harmful ultraviolet radiation from the sun.
• Pollutant at Ground Level: While beneficial up above, ozone at the surface level is a harmful pollutant, contributing to smog.
• Distinctive Smell: Ozone can be detected by its sharp odor often noticed after thunderstorms or around electrical equipment.

Understanding ozone's structure and properties is crucial for grasping its impact on health and the environment. This knowledge not only highlights the different roles ozone plays but also underscores the importance of chemistry in our everyday life.

Chemical Formulas

Chemical formulas are shorthand notations that convey information about the composition of a chemical compound. They provide a quick way to identify the types and quantities of atoms in a molecule. Taking the ozone molecule \(O_3\) as an example, the chemical formula conveys the following:

• Element Identification: The letter "O" stands for oxygen, indicating the type of atoms present.
• Subscript Number: The subscript "3" tells us there are three oxygen atoms in the molecule.

Chemical formulas range from simple, like \(H_2\) for hydrogen, to complex polymers containing multiple types of atoms. By learning to read and understand these formulas, you develop a skill crucial for decoding the specifics of chemical reactions and processes. This knowledge can open doors to exploring more complex chemical concepts and applications.