Chapter 14: Environmental Chemistry

NCERT Solutions for Class 11 Chemistry Chapter 14 - Environmental Chemistry

Environmental Chemistry might seem like a straightforward descriptive chapter, but it carries significant marks in board exams and often includes application-based questions that students are unprepared for. Understanding the difference between primary and secondary pollutants, the chemistry behind the formation of smog and acid rain, the role of CFCs in ozone depletion, and the toxicological effects of heavy metals requires more than just reading - it requires understanding the underlying chemical reactions and mechanisms. 

The NCERT solutions for Class 11 Chemistry Chapter 14 Environmental Chemistry on Myclass24 are written to give you exactly that understanding. These solutions explain not just what happens but why it happens chemically - from the chain reactions of ozone destruction to the formation of biochemical oxygen demand in water bodies. For students who want to score full marks in this chapter and also develop genuine awareness about environmental issues, the detailed and accurate solutions on Myclass24 are an excellent resource.

Download NCERT Solutions for Class 11 Chemistry Chapter 14 Environmental Chemistry PDF

The PDF of NCERT Solutions for Class 11 Chemistry Chapter 14 Environmental Chemistry is freely available on Myclass24. It includes complete answers to all NCERT exercise questions on atmospheric pollution, water pollution, soil pollution, and green chemistry principles.

Chapter 14 Environmental Chemistry - Concepts, Facts and Key Tables

Environmental Chemistry studies the chemical phenomena in the natural environment and the impact of human activities on it. Chapter 14 covers four major types of pollution: atmospheric, water, soil, and introduces the concept of green chemistry as a constructive solution. One can check out all chapters of NCERT Solutions for Class 11 Chemistry and all subjects of NCERT Solutions for Class 11 from the Myclass24 page. 

The atmosphere is divided into layers: troposphere (0-12 km, weather occurs here), stratosphere (12-50 km, contains the ozone layer), mesosphere (50-85 km), thermosphere (85-500 km), and exosphere. Tropospheric pollution involves gaseous pollutants - oxides of sulphur (SO2, SO3 producing acid rain), oxides of nitrogen (NO, NO2 contributing to photochemical smog), carbon monoxide (CO binds haemoglobin 200 times more strongly than O2, causing CO poisoning), hydrocarbons, and particulate matter. Global warming is primarily driven by greenhouse gases: CO2 (most significant anthropogenically), CH4, N2O, and CFCs.

Photochemical smog (Los Angeles type) forms when NOx and hydrocarbons react in sunlight to produce ozone (at ground level it is a pollutant), PAN (peroxyacetyl nitrate - a secondary pollutant irritating to eyes and lungs), and other oxidants. Classical smog (London type, sulphurous smog) forms from SO2 and particulate matter in cold, humid conditions. Stratospheric ozone depletion: CFCs (freons) are the primary culprits. In the stratosphere, UV radiation breaks CFCs to release Cl atoms, which destroy ozone in a chain reaction. One chlorine atom can destroy approximately 100,000 ozone molecules. The Montreal Protocol (1987) phased out CFC production globally.

Water pollution covers BOD (Biochemical Oxygen Demand - a measure of organic pollution; clean water less than 5 ppm, severely polluted water more than 17 ppm), heavy metal toxicity (Hg, Pb, Cd, As), eutrophication (excessive algal growth due to nutrient runoff), and fluorosis from excess fluoride. Soil pollution includes pesticides (DDT is a persistent organic pollutant), industrial effluents, and radioactive waste. Green Chemistry principles aim to design chemical processes that minimise hazardous substances at source.

Atmospheric Layers and Associated Chemistry

Types of Smog - Comparison

Common Air Pollutants and Their Effects