Land Pollution, Water Pollution - Free MCQ Practice Test with solutions,

Incorrect Information about DDT

• Organic Pollutant: This is correct, DDT is classified as an organic pollutant due to its chemical structure and environmental impact.
• p - p - dichloro diphenyl ethane: This is incorrect. The correct chemical name for DDT is p,p'-dichlorodiphenyltrichloroethane.
• Contains two Benzene rings & 5 halogen atoms: This is correct. DDT consists of two benzene rings and five halogen atoms, which contribute to its chemical structure and properties.
• Replaced by Aldrin in pesticides to decrease water pollution: This is incorrect. Aldrin is a separate pesticide that was used in the past but has been banned due to environmental concerns. DDT, on the other hand, has also been banned in many countries due to its harmful effects on wildlife and the environment.

Fuel obtained from plastic waste

• Green fuel is the fuel obtained from plastic waste that contains no lead.
• This type of fuel is considered environmentally friendly as it helps in recycling used plastic and reducing waste in landfills.
• The process of converting plastic waste into green fuel involves pyrolysis, which is a method of heating the plastic to high temperatures in the absence of oxygen to break it down into fuel.
• The resulting green fuel can be used as a substitute for traditional fossil fuels in various applications such as heating, electricity generation, and transportation.
• Green fuel has the potential to reduce greenhouse gas emissions and decrease our reliance on non-renewable energy sources.

Excessive concentration of nitrate in drinking water is harmful and can cause methemoglobinemia (blue baby syndrome).

Decrease in D.O causes death of fish

The amount of oxygen required by bacteria to break down the organic matter present in a certain volume of a sample of water is called biochemical oxygen demand (BOD). The amount of BOD in the water is a measure of the amount of organic material in water in terms of how much oxygen will be required to break it down biologically. Clean water have BOD value less than 5ppm whereas highly polluted water such as municipal sewage has BOD value more than 100ppm.

BOD is connected with microbes and organic matter

Actual ammount of dissolved oxygen(DO) varies according to temperature. In cold water, dissolved oxygen (DO) can reach a concentration upto 10ppm.

Particulates acquire negative charge and are attracted by the positive electrode.

Oil slick in sea water decreases D.O value.

For statement (iii), Methemoglobinemia (blue baby syndrome) is caused due to excess of nitrate in drinking water. For statement (iv), Excessive sulphate (> 500ppm ) in drinking water causes laxative effect, otherwise at moderate levels it is harmless.

BOD (Biochemical Oxygen Demand)

• BOD refers to the amount of oxygen that microorganisms require to decompose organic matter present in water.
• It is a measure of the organic pollutants in water that can be decomposed by bacteria and other microorganisms.
• High BOD levels indicate high levels of organic pollutants in water, which can lead to oxygen depletion and harm aquatic life.
• BOD is typically measured over a specific period, such as 5 days (BOD5), to determine the oxygen demand for decomposition.
• By measuring BOD, water quality can be assessed, and appropriate measures can be taken to prevent pollution and protect aquatic ecosystems.

Detergents used in hair conditioners:

• Cationic detergents: Cationic detergents are often used in hair conditioners because they are positively charged and can easily bind to the negatively charged surface of hair strands. This helps to reduce friction between hair strands, making them easier to comb and style. Cationic detergents also help to smooth the cuticle layer of the hair, making it look shinier and feel softer.
• Anionic detergents: Anionic detergents are not typically used in hair conditioners as they can strip away natural oils from the hair, leading to dryness and damage.
• Nonionic detergents: Nonionic detergents are also not commonly used in hair conditioners as they do not have the same conditioning properties as cationic detergents.
• Synthetic detergents: Synthetic detergents may be used in some hair conditioners to help clean the hair and scalp without stripping away too much natural oil. However, they are not as effective at providing conditioning benefits as cationic detergents.

Freons only cause air pollution.

water of
water of
of requires
of will required

The excessive growth of algae and aquatic plants due to nutrients present in a lake is called eutrophication.

Nitrogen and phosphorus fertilizers which are drained from agricultural lands into water bodies cause eutrophication.

• pH of Acid Rain: The pH of acid rain is typically around 5. This means that acid rain is slightly acidic, with a pH lower than pure water.
• Acidic Nature: Acid rain is caused by pollutants in the atmosphere, such as sulfur dioxide and nitrogen oxides, that react with water vapor to form sulfuric acid and nitric acid. These acids lower the pH of rainwater.
• pH Scale: The pH scale measures the acidity or basicity of a solution. A pH of 7 is considered neutral, while values below 7 are acidic and values above 7 are basic.
• Impact: Acid rain can have harmful effects on the environment, including damage to forests, crops, and aquatic ecosystems. It can also contribute to the corrosion of buildings and infrastructure.

Chlorine kills germs present in water.

Pesticides and synthetic fertilizers pollute the soil.

Phosphate pollution is caused by sewage and agricultural fertilizers.