Scoring well in JEE Mains 2026 depends not only on hard chapters but also on those small chapters that give sure-shot marks. Environmental Chemistry is one such chapter. It is short, easy, and highly predictable. Every year, at least one or two direct questions are asked from this topic, and students who prepare it properly never miss those marks. This detailed guide on Top Environmental Chemistry JEE Mains Questions for 2026 – Concept-Based Practice Set is written to help you understand concepts clearly, practice the right type of questions, and improve your Chemistry score with confidence. Everything is explained in very simple English so that even average students can master this chapter without stress.
Environmental Chemistry does not involve long calculations. It is based on real-life environmental issues and basic chemical principles. With focused study and correct revision, this chapter can become one of the easiest ways to increase your total score in JEE Mains 2026.
Why Environmental Chemistry Is a Smart Scoring Chapter
Environmental Chemistry offers high return for very little effort. The syllabus is limited, questions are direct, and most answers come straight from NCERT. The exam pattern of JEE Mains shows that this chapter appears almost every year with one or two MCQs. Many students ignore it, but those who take it seriously gain an advantage over thousands of competitors.
Most Environmental Chemistry JEE Mains questions test understanding of pollution types, definitions, environmental problems, and protection methods. Since there are no lengthy calculations, it becomes an ideal chapter for quick revision before the exam.
What You Must Study in Environmental Chemistry
The entire Environmental Chemistry syllabus for JEE Mains includes:
• Air pollution
• Water pollution
• Soil contamination
• Industrial waste
• Greenhouse effect
• Global warming
• Depletion of ozone layer
• Acid rain
• Photochemical smog
• Principles of green chemistry
• BOD and COD
• Eutrophication
• Solid waste disposal
• Role of chemistry in protecting the environment
Almost all Environmental Chemistry JEE Mains questions are directly created from these topics.
Air Pollution – Key Concepts
Air pollution occurs when harmful substances mix with air in amounts that damage human health, nature, and materials. The major pollutants are carbon monoxide, sulfur dioxide, nitrogen oxides, hydrocarbons, ozone, and particulate matter.
Carbon monoxide is dangerous because it combines strongly with hemoglobin, reducing oxygen supply to the body. Sulfur dioxide mainly comes from burning coal and petroleum and causes breathing problems. Nitrogen oxides participate in smog formation and acid rain.
This topic is a regular source of Environmental Chemistry JEE Mains questions.
Practice
Q1. Which gas blocks oxygen transport in blood?
Answer: Carbon monoxide
Q2. Which nitrogen compound gives brown color to polluted air?
Answer: Nitrogen dioxide
Q3. Which gases are responsible for acid rain?
Answer: Sulfur dioxide and nitrogen oxides
Water Pollution – Important Theory
Water becomes polluted when harmful chemicals, sewage, pesticides, fertilizers, and industrial waste enter rivers, lakes, and seas. This reduces oxygen levels and destroys aquatic life.
Biochemical Oxygen Demand (BOD) measures how much oxygen bacteria need to break down organic matter in water. High BOD means water is highly polluted. Chemical Oxygen Demand (COD) measures oxygen required to oxidize all substances in water.
These definitions are common in Environmental Chemistry JEE Mains questions.
Practice
Q4. High BOD value shows?
Answer: High organic pollution
Q5. COD measures?
Answer: Total oxidizable pollutants
Q6. Excess nutrients in water cause?
Answer: Eutrophication
Soil Pollution – Core Points
Soil gets polluted when harmful chemicals such as pesticides, fertilizers, heavy metals, and industrial waste mix with it. Toxic substances accumulate and move into the food chain.
Mercury causes Minamata disease, while DDT shows biomagnification.
Practice
Q7. Minamata disease is caused by?
Answer: Mercury
Q8. Which pesticide accumulates in food chain?
Answer: DDT
Greenhouse Effect and Global Warming
Certain gases trap heat in the atmosphere. These are called greenhouse gases. The major ones are carbon dioxide, methane, nitrous oxide, and water vapor. This heat trapping leads to global warming, melting glaciers, rising sea level, and climate disturbances.
Practice
Q9. Strongest greenhouse gas among common ones?
Answer: Methane
Q10. Main cause of global warming?
Answer: Increase in CO₂ level
Ozone Layer and Its Depletion
The ozone layer protects living beings from harmful ultraviolet radiation. Chemicals like CFCs release chlorine atoms that destroy ozone molecules.
Practice
Q11. Which chemicals destroy ozone?
Answer: CFCs
Q12. Ozone depletion increases risk of?
Answer: Skin cancer
Acid Rain
Acid rain is formed when sulfur dioxide and nitrogen oxides dissolve in rainwater to form sulfuric acid and nitric acid. It damages plants, soil, buildings, and aquatic ecosystems.
Practice
Q13. Normal acid rain pH is less than?
Answer: 5.6
Photochemical Smog
Smog is produced when nitrogen oxides and hydrocarbons react in sunlight forming ozone and PAN. PAN is responsible for eye irritation and breathing problems.
Practice
Q14. Eye irritation in smog is caused by?
Answer: PAN
Solid Waste Management
Solid waste includes household garbage, plastics, metals, and biodegradable materials. Pollution can be controlled by recycling, composting, controlled burning, and landfill methods.
Practice
Q15. Best method for reducing solid waste pollution?
Answer: Recycling
Green Chemistry
Green chemistry promotes chemical processes that reduce or eliminate toxic substances. Its aim is to protect the environment and human health.
Practice
Q16. Main aim of green chemistry?
Answer: Prevent pollution
How to Score High from Environmental Chemistry
To master Environmental Chemistry JEE Mains questions, always read NCERT thoroughly. Focus on definitions, causes, effects, and preventive methods. Practice MCQs daily. Revise this chapter frequently as it is memory-based.
Final Revision Plan
Read NCERT carefully
Revise definitions regularly
Practice MCQs
Revise one day before exam
Attempt this chapter early in exam
Final Words
Environmental Chemistry is one of the easiest chapters to score in JEE Mains 2026. With proper concept understanding and regular practice of the Top Environmental Chemistry JEE Mains Questions for 2026 – Concept-Based Practice Set, you can secure these marks with confidence. This chapter strengthens your overall score and gives you an edge over many competitors.
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