Problem 12 - A Complete Resource Book in Chemistry for JEE Main

Question

The major components of the atmosphere are (a) \(\mathrm{CO}_{2}\) and \(\mathrm{N}_{2}\) (b) \(\mathrm{O}_{3}\) and \(\mathrm{SO}_{2}\) (c) \(\mathrm{CO}\) and \(\mathrm{CO}_{2}\) (d) \(\mathrm{N}_{2}^{3}\) and \(\mathrm{O}_{2}\)

Step-by-Step Solution

Answer

The major components of the atmosphere are (d) \( ext{N}_2\) and \( ext{O}_2\).

Step 1: Understanding Atmosphere Composition

To solve this problem, we need to understand the major components of Earth's atmosphere. Earth's atmosphere is primarily composed of the gases nitrogen (\( ext{N}_2\)) and oxygen (\( ext{O}_2\)), with nitrogen making up about 78% and oxygen about 21%.

Step 2: Analyze Answer Choices

Now, let's evaluate each option. - Option (a): \( ext{CO}_2\) and \( ext{N}_2\) lists carbon dioxide, which is not a major component, as it is present in trace amounts.- Option (b): \( ext{O}_3\) (ozone) and \( ext{SO}_2\) (sulfur dioxide), both occur in trace amounts in the atmosphere.- Option (c): \( ext{CO}\) and \( ext{CO}_2\) are both trace gases.- Option (d): \( ext{N}_2\) and \( ext{O}_2\) are the main components, though the notation \( ext{N}_2^3\) is incorrect, we consider \( ext{N}_2\) as the intended notation for nitrogen.

Step 3: Identify the Correct Choice

Based on the composition of the atmosphere, option (d) is the most correct. However, the labeling \( ext{N}_2^3\) appears inaccurate but is assumed to represent \( ext{N}_2\), which is nitrogen, a major component along with \( ext{O}_2\) (oxygen).

Key Concepts

Nitrogen Gas

Nitrogen gas plays a crucial role in the atmosphere, making up about 78% of Earth's air. It is a colorless, odorless gas vital for life on Earth, as it serves as a building block of proteins and nucleic acids.
The inert nature of nitrogen makes it stable and non-reactive under normal atmospheric conditions, which helps create a balanced and protective environment for living organisms.
Nitrogen moves through an essential cycle. Plants take up nitrogen from the soil in a form they can use (nitrates), and animals obtain it through their diet. When organisms decompose, nitrogen returns to the soil, continuing the cycle. This process ensures that life on Earth has a continuous supply of nitrogen.

Oxygen Gas

Oxygen gas is the second most abundant component of the Earth's atmosphere, comprising approximately 21% of it. This gas is crucial for respiration, a process in which living organisms convert oxygen into energy.
Oxygen is not only vital for animals and plants but also plays a significant role in the chemical processes of the Earth. It participates in combustion reactions and is an integral part of the water molecule, \[H_2O\].
Plants contribute to the oxygen levels in the atmosphere through photosynthesis. They absorb carbon dioxide and, using sunlight, produce oxygen as a byproduct. This cycle maintains Earth's balanced and habitable atmosphere, allowing for diverse life forms to flourish.

Trace Gases

Besides nitrogen and oxygen, the Earth's atmosphere contains trace gases. Although present in small amounts (often less than 1% of the atmosphere), these gases have significant impacts.
Some common trace gases include:

• Carbon Dioxide (\(CO_2\))
• Ozone (\(O_3\))
• Methane (\(CH_4\))
• Noble gases like argon (\(Ar\))

These gases are essential in their various roles:

• \(CO_2\) is vital for plant photosynthesis and contributes to the greenhouse effect, regulating Earth's temperature.
• Ozone protects the planet from harmful ultraviolet rays.
• Methane is a potent greenhouse gas with a significant heat-trapping ability.

Even in minuscule concentrations, trace gases influence climate, weather patterns, and the overall health of the biosphere.