Science chapter practice
Practise 80+ Chemistry in Everyday Life MCQs for UPSC Prelims in Science, including 44+ previous year questions. The sample set below is shown with correct answers and explanations.
12 sample questions are shown here; sign up free to practise all 80.
Consider the following substances: 1. Ethanol 2. Nitroglycerine 3. Urea Coal gasification technology can be used in the production of how many of them?
Explanation
Correct. Coal gasification yields synthesis gas, which can be catalytically converted to ethanol, used to produce ammonia for urea, and processed into nitroglycerine precursors.
Consider the following statements: 1. Carbon fibres are used in the manufacture of components used in automobiles and aircraft. 2. Carbon fibres once used cannot be recycled. Which of the statements given above is/are correct?
Explanation
Correct. Carbon fibres are widely used in automobile and aircraft components for their high strength-to-weight ratio. However, carbon fibre recycling technologies (pyrolysis, solvolysis) do exist, making statement 2 incorrect.
With reference to polyethylene terephthalate, the use of which is so widespread in our daily lives, consider the following statements: 1. Its fibres can be blended with wool and cotton fibres to reinforce their properties. 2. Containers made of it can be used to store any alcoholic beverage. 3. Bottles made of it can be recycled into other products. 4. Articles made of it can be easily disposed of by incineration without causing greenhouse gas emissions. Which of the statements given above are correct?
Explanation
Correct. PET fibres (polyester) are commonly blended with wool and cotton. PET bottles are among the most widely recycled plastics. However, PET is not suitable for storing all alcoholic beverages (especially spirits), and incineration of PET does produce CO₂.
Water can dissolve more substances than any other liquid because:
Explanation
Correct. Water molecules are dipolar (have partial positive and negative charges), enabling them to surround and dissolve a wide range of ionic and polar substances, making water the 'universal solvent'.
Bisphenol A (BPA), a cause of concern, is a structural/key component in the manufacture of which of the following kinds of plastics?
Explanation
Correct. BPA is a key monomer used in the manufacture of polycarbonate plastics, which are used in water bottles, food containers, and CDs.
In the context of which one of the following are the terms 'pyrolysis and plasma gasification' mentioned?
Explanation
Correct. Pyrolysis (thermal decomposition without oxygen) and plasma gasification (using ionised gas at extreme temperatures) are advanced waste-to-energy technologies that convert solid waste into syngas and other useful products.
Consider the following pairs: Commonly used/consumed materials — Unwanted or controversial chemicals likely to be found in them 1. Lipstick — Lead 2. Soft drinks — Brominated vegetable oils 3. Chinese fast food — Monosodium glutamate Which of the pairs given above is/are correctly matched?
Explanation
Correct. Studies have found trace amounts of lead in lipsticks, BVO has been used in some soft drinks as a flavour emulsifier, and MSG is a common flavour enhancer in Chinese fast food.
With reference to 'fuel cells' in which hydrogen-rich fuel and oxygen are used to generate electricity, consider the following statements: 1. If pure hydrogen is used as a fuel, the fuel cell emits heat and water as by-products. 2. Fuel cells can be used for powering buildings and not for small devices like laptop computers. 3. Fuel cells produce electricity in the form of Alternating Current (AC). Which of the statements given above is/are correct?
Explanation
Correct. When pure hydrogen reacts with oxygen in a fuel cell, the only by-products are heat and water. Fuel cells can power devices of all sizes (not just buildings), and they produce DC, not AC.
Which of the following is/are the example/examples of chemical change? 1. Crystallization of sodium chloride 2. Melting of ice 3. Souring of milk Select the correct answer using the code given below.
Explanation
Correct. Souring of milk is a chemical change because lactose is converted into lactic acid by bacterial action, producing a new substance. Crystallization and melting are physical changes.
Fruits stored in cold chambers exhibit long storage life because:
Explanation
Correct. Low temperatures in cold chambers slow down the rate of cellular respiration in fruits, reducing the production of ethylene and other ripening agents, thereby extending shelf life.
Aspartame is an artificial sweetener sold in the market. It consists of amino acids and provides calories like other amino acids. Yet, it is used as a low-calorie sweetening agent in food items. What is the basis of this use?
Explanation
Correct. Aspartame is approximately 200 times sweeter than sucrose, so only tiny amounts are needed to achieve the same sweetness, resulting in negligible caloric intake.
Excessive release of the pollutant carbon monoxide (CO) into the air may produce a condition in which oxygen supply in the human body decreases. What causes this condition?
Explanation
Correct. Carbon monoxide has about 200-250 times greater affinity for haemoglobin than oxygen, forming carboxyhaemoglobin and preventing oxygen transport.
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