Question

Which of the following is not an air pollutant? (a) \(\mathrm{N}_{2} \mathrm{O}\) (b) \(\mathrm{N}_{2}\) (c) \(\mathrm{CO}\) (d) \(\mathrm{NO}\)

Short answer

(b) \(\mathrm{N}_2\) is not an air pollutant.

Step-by-step solution

Identify Potential Air Pollutants

Air pollutants are substances that can cause harm or discomfort to humans, other living organisms, or the natural environment. Common air pollutants include gases such as carbon monoxide ( CO ), nitrogen oxides like NO and N_2O , and particulates. Let's evaluate which are typically considered pollutants.

Evaluate Each Option

- N_2O (nitrous oxide) is a greenhouse gas and a pollutant. - N_2 (nitrogen gas) makes up 78% of Earth's atmosphere and is not considered a pollutant. - CO (carbon monoxide) is a toxic gas and a known pollutant. - NO (nitric oxide) is a pollutant, contributing to smog and acid rain.

Identify the Non-Pollutant

From the evaluation above, we notice that N_2 , being the major component of the atmosphere and non-reactive under normal conditions, is not considered an air pollutant. All other options are recognized as pollutants.

Key concepts

Air Pollutants

Air pollutants are substances in the air that can harm health or the environment. They can come from both natural sources, like volcanoes, and human activities, such as burning fossil fuels. Some common air pollutants include:

• Carbon Monoxide (CO): A colorless, odorless gas, it is toxic and can lead to severe health issues, like impaired brain function.
• Nitrogen Oxides (NO and NO₂): These contribute to smog and acid rain, impacting respiratory health and damaging the environment.
• Particulate Matter: Tiny particles in the air that can penetrate deep into the lungs, causing health problems.

It’s important to manage and reduce air pollutants because they worsen air quality and pose risks to both humans and the broader ecosystem.

Environmental Chemistry

Environmental chemistry is the study of chemical processes occurring in the environment. It focuses on understanding how various substances interact with air, water, soil, and living organisms. This field helps identify the presence and effects of pollutants. Key topics in environmental chemistry include:

• Pollution Sources: Understanding where pollutants come from, such as industrial processes and vehicle emissions.
• Chemical Reactions: Analyzing how pollutants degrade and react in the environment, forming secondary pollutants like ozone.
• Impact Assessment: Evaluating the ecological and health implications of pollutants.

By studying environmental chemistry, scientists devise strategies to mitigate pollution, promote sustainability, and protect natural resources.

Greenhouse Gases

Greenhouse gases are molecules in the atmosphere that trap heat, keeping the Earth warm. While they're essential for life, excessive amounts can lead to global warming. Key greenhouse gases include:

• Carbon Dioxide (CO₂): Released by burning fossil fuels, it is the primary contributor to the greenhouse effect.
• Methane (CH₄): Emitted during oil and gas production and by agriculture, it is much more effective at trapping heat than CO₂ but present in smaller quantities.
• Nitrous Oxide (N₂O): A byproduct of agricultural activities and industrial processes, it is also a potent greenhouse gas.

Managing greenhouse gas emissions is crucial for tackling climate change and ensuring a stable climate for future generations.