Environmental and Industrial Chemistry MCQs 2026

Sewage treatment that uses microorganisms to break down waste is called

1. A biological treatment ✓
2. B distillation ✓
3. C filtration only ✓
4. D chlorination only ✓

The greenhouse effect is worsened by rising gases such as CO2 and

1. A oxygen ✓
2. B methane ✓
3. C nitrogen ✓
4. D argon ✓

The industrial preparation of nitric acid from ammonia is called the

1. A Contact process ✓
2. B Haber process ✓
3. C Ostwald process ✓
4. D Solvay process ✓

Green chemistry mainly aims to

1. A increase pollution ✓
2. B waste resources ✓
3. C use more toxic solvents ✓
4. D reduce or prevent pollution ✓

Burning fossil fuels adds to the atmosphere large amounts of

1. A carbon dioxide ✓
2. B oxygen ✓
3. C helium ✓
4. D argon ✓

COD in water analysis stands for Chemical Oxygen

1. A Deficiency ✓
2. B Demand ✓
3. C Density ✓
4. D Dioxide ✓

The colourless, poisonous gas from incomplete combustion of fuels is

1. A carbon dioxide ✓
2. B oxygen ✓
3. C carbon monoxide ✓
4. D nitrogen ✓

Nitrogenous fertilizers such as urea supply the essential element

1. A phosphorus ✓
2. B potassium ✓
3. C calcium ✓
4. D nitrogen ✓

The main component of natural gas used as an industrial fuel is

1. A ethane ✓
2. B methane ✓
3. C propane ✓
4. D butane ✓

Recycling materials such as glass and metals helps to

1. A increase waste ✓
2. B waste energy ✓
3. C conserve natural resources ✓
4. D raise pollution ✓

The vehicle-emitted gas that reduces the oxygen-carrying capacity of blood is

1. A oxygen ✓
2. B carbon monoxide ✓
3. C nitrogen ✓
4. D hydrogen ✓

The process used to soften hard water by removing calcium and magnesium ions is

1. A ion exchange ✓
2. B chlorination ✓
3. C aeration ✓
4. D sedimentation ✓

A biodegradable waste is one that can be broken down by

1. A plastic ✓
2. B glass ✓
3. C metal ✓
4. D microorganisms ✓

Treating water by allowing suspended particles to settle is called

1. A sedimentation ✓
2. B chlorination ✓
3. C aeration ✓
4. D distillation ✓

The gas with a rotten-egg smell linked to some industrial pollution is

1. A carbon dioxide ✓
2. B methane ✓
3. C oxygen ✓
4. D hydrogen sulfide ✓

In the Haber process, nitrogen combines with

1. A oxygen ✓
2. B chlorine ✓
3. C hydrogen ✓
4. D carbon ✓

A greenhouse gas released mainly from paddy fields and livestock is

1. A oxygen ✓
2. B argon ✓
3. C neon ✓
4. D methane ✓

Photochemical smog is mainly formed from vehicle emissions and

1. A sunlight ✓
2. B rainfall ✓
3. C snow ✓
4. D darkness ✓

The chemical commonly added to drinking water to kill germs is

1. A ammonia ✓
2. B carbon dioxide ✓
3. C chlorine ✓
4. D nitrogen ✓

The excessive growth of algae in water due to nutrient pollution is called

1. A fermentation ✓
2. B chlorination ✓
3. C filtration ✓
4. D eutrophication ✓

BOD stands for Biochemical Oxygen

1. A Deficiency ✓
2. B Demand ✓
3. C Density ✓
4. D Dioxide ✓

A major water pollutant from untreated sewage that lowers dissolved oxygen is

1. A sand ✓
2. B plastic ✓
3. C organic waste ✓
4. D glass ✓

The gas released by burning fossil fuels that causes the greenhouse effect is

1. A carbon dioxide ✓
2. B nitrogen ✓
3. C hydrogen ✓
4. D neon ✓

The Solvay process is used to manufacture

1. A ammonia ✓
2. B sulfuric acid ✓
3. C nitric acid ✓
4. D sodium carbonate (washing soda) ✓

The catalyst used in the Haber process is finely divided

1. A nickel ✓
2. B iron ✓
3. C copper ✓
4. D zinc ✓

The catalyst used in the Contact process is

1. A vanadium pentoxide (V2O5) ✓
2. B iron ✓
3. C nickel ✓
4. D platinum only ✓

The most abundant gas in the Earth's atmosphere is

1. A oxygen ✓
2. B carbon dioxide ✓
3. C nitrogen ✓
4. D argon ✓

The main greenhouse gas responsible for global warming is

1. A carbon dioxide ✓
2. B oxygen ✓
3. C nitrogen ✓
4. D helium ✓

The atmospheric layer that protects us from ultraviolet radiation is the

1. A nitrogen layer ✓
2. B ozone layer ✓
3. C carbon layer ✓
4. D oxygen layer ✓

Chemicals mainly responsible for ozone depletion are

1. A oxides of iron ✓
2. B carbonates ✓
3. C nitrates ✓
4. D chlorofluorocarbons (CFCs) ✓

Acid rain is mainly caused by oxides of sulfur and

1. A carbon ✓
2. B hydrogen ✓
3. C sodium ✓
4. D nitrogen ✓

The pH of acid rain is generally

1. A equal to 7 ✓
2. B below 7 ✓
3. C above 7 ✓
4. D exactly 14 ✓

The Haber process is used to manufacture

1. A ammonia ✓
2. B sulfuric acid ✓
3. C nitric acid ✓
4. D cement ✓

Which metal is a toxic heavy-metal water pollutant

1. A sodium ✓
2. B lead ✓
3. C potassium ✓
4. D calcium ✓

The Contact process is used to manufacture

1. A ammonia ✓
2. B nitric acid ✓
3. C sulfuric acid ✓
4. D sodium carbonate ✓

The manufacture of sulfuric acid, ammonia and cement are examples of

1. A biological processes ✓
2. B natural weathering ✓
3. C industrial chemical processes ✓
4. D household activities ✓

The greenhouse gas nitrous oxide is mainly released from

1. A volcanoes only ✓
2. B the ocean ✓
3. C fertilizers and farming ✓
4. D rainwater ✓

The gas responsible for ozone-layer depletion contains the element

1. A sulfur ✓
2. B carbon ✓
3. C nitrogen ✓
4. D chlorine ✓

Non-biodegradable waste includes materials such as

1. A vegetable peels ✓
2. B plastics ✓
3. C paper ✓
4. D leaves ✓

PVC, a common plastic, is made by polymerising

1. A vinyl chloride ✓
2. B ethene ✓
3. C propene ✓
4. D methane ✓

Polythene (polyethylene) is a polymer made from

1. A propene ✓
2. B styrene ✓
3. C ethene ✓
4. D benzene ✓

The lightest fraction obtained from the fractional distillation of petroleum is

1. A diesel ✓
2. B kerosene ✓
3. C bitumen ✓
4. D petroleum gas ✓

Petroleum is separated into useful fractions by

1. A filtration ✓
2. B fractional distillation ✓
3. C crystallisation ✓
4. D evaporation ✓

The main raw material for the manufacture of cement is

1. A limestone ✓
2. B common salt ✓
3. C sulfur ✓
4. D ammonia ✓

The process of removing salt from seawater to obtain fresh water is called

1. A filtration ✓
2. B chlorination ✓
3. C desalination ✓
4. D sedimentation ✓