Q: Water can dissolve more substances than any other liquid because
(a)it is dipolar in nature
(b)it is a good conductor of heat
(c)it has high value of specific heat
(d)it is an oxide of hydrogen
Loading...
Chemistry — UPSC Prelims Previous Year Questions
51 questions from UPSC CSE Prelims GS Paper 1 on Chemistry (Science & Technology). Spanning from 1995 to 2021. Practice with show/hide answers and detailed explanations.
51
Questions
18
Years
36
Easy
15
Moderate
Year-wise Distribution
What UPSC Asks About Chemistry
Based on 51 questions across 18 years, UPSC has consistently tested aspirants' understanding of Chemistry within the broader Science & Technology syllabus. The questions range from factual recall to application-based analysis.
Recent trends show UPSC moving towards statement-based questions that combine multiple aspects of Chemistry. Aspirants should focus on understanding concepts rather than memorizing isolated facts.
Related Science & Technology Sub-topics
All Chemistry Questions
Q: भारत में कार्बोफ्यूरान, मेथिल पैराक्विन, फोरेट और ट्रायबोफॉस के उपयोग को अक्सर देखा जाता है। ये रसायन किस रूप में इस्तेमाल किए जाते हैं?
(a)कृषि में कीटनाशी
(b)संग्रहीत खाद्य में परिरक्षक
(c)फल-पकाने कारक
(d)प्रसाधन सामग्री में रंग बनाने वाले कारक
Q: 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.
(a)1 and 2 only
(b)3 only
(c)1, 2 and 3
(d)None
Q: Chlorination is a process used for water purification. The disinfecting action of chlorine is mainly due to
(a)The formation of hydrochloric acid when chlorine is added to water
(b)The formation of hypochlorous acid when chlorine is added to water
(c)The formation of nascent oxygen when chlorine is added to water
(d)The formation of hydrogen when chlorine is added to water
Q: Which one of the following is used as an explosive ?
(a)Phosphorus trichloride
(b)Mercuric oxide
(c)Graphite
(d)Nitroglycerine
Q: What is Bisphenol A (BPA)?
(a)A medical test for detecting cancer
(b)A test for testing the use of drugs to improve performance by athletes
(c)A chemical used for the development of food-packaging materials
(d)A special type of alloy steel
Q: What is Agent Orange?
(a)An ace spying group trained by the Police in London
(b)A weed-killing chemical used by the US Military in the Vietnam War
(c)A technique used in the advanced railway safety procedure
(d)A special chemical used in making alloy steel
Q: Who among the following discovered heavy water?
(a)Heinrich Hertz
(b)H. C. Urey
(c)G. Mendel
(d)Joseph Priestley
Q: Which one of the following is also called Stranger Gas?
(a)Argon
(b)Neon
(c)Xenon
(d)Nitrous oxide
Q: Which one of the following pairs of metals constitutes the lightest metal and the heaviest metal, respectively?
(a)Lithium and mercury
(b)Lithium and osmium
(c)Aluminium and osmium
(d)Aluminium and mercury
Q: Which one of the following is another name of RDX?
(a)Cyanohydrin
(b)Dextran
(c)Cyclohexane
(d)Cyclonite
Q: Which one of the following is called Philosopher’s wool?
(a)Zinc Bromide
(b)Zinc Nitrate
(c)Zinc Oxide
(d)Zinc Chloride
Q: Which one of the following does not contain silver?
(a)Horn Silver
(b)German Silver
(c)Ruby Silver
(d)Lunar Caustic
Q: Consider the following chemicals: 1. Benzene 2. Carbon tetrachloride 3. Sodium carbonate 4. Trichloroethylene Which of the above is/are used as dry-cleaning chemicals?
(a)1 only
(b)2 only
(c)1, 2 and 4 only
(d)1, 2, 3 and 4
Q: Consider the following statements : 1. Anhydrous sodium carbonate is commonly known as baking soda 2. Baking soda is used in fire extinguishers 3. Bleaching powder is manufactured in Hasenclever plant Which of the statements given above is/are correct?
(a)1, 2 and 3
(b)2 and 3
(c)3 only
(d)1 and 2
Q: Consider the following statements: 1. Banking soda is used in fire extinguishers. 2. Quicklime is used in the manufacture of glass. 3. Gypsum is used in the manufacture of Plaster of Paris. Which of the statements given above is/are correct?
(a)1 and 2
(b)2 and 3
(c)1 only
(d)1, 2 and 3
Q: Salts of which of the following elements provide colours to fireworks?
(a)Zinc and sulphur
(b)Potassium and mercury
(c)Strontium and barium
(d)Chromium and nickel
Q: Which one of the following statements is correct?
(a)Liquid sodium is employed as a coolant in nuclear reactors
(b)Calcium carbonate is an ingredient of toothpaste
(c)Bordeaux mixture consists of sodium sulphate and lime
(d)Zinc amalgams are used as a dental filling
Q: Consider the following statements The purpose of adding sodium sulphate and sodium silicate to the detergent in a washing powder is 1. To keep the washing powder dry 2. To maintain the alkalinity of the powder Which of these statements is/are correct?
(a)Only 1
(b)Only 2
(c)Both 1 and 2
(d)Neither 1 nor 2
Q: Assertion (A): In the periodic table of chemical elements, electron affinity is always found to increase from top to bottom in a group. Reason (R): In a group, the atomic radius generally increases from top to bottom.
(a)Both A and R are individually true and R is the correct explanation of A
(b)Both A and R are individually true but R is NOT the correct explanation of A
(c)A is true but R is false
(d)A is false but R is true
Q: Assertion (A): Unsaturated fats are more reactive compared with the saturated fats. Reason (R): Unsaturated fats have only single bonds in their structure.
(a)Both A and R are individually true and R is the correct explanation of A
(b)Both A and R are individually true but R is NOT the correct explanation of A
(c)A is true but R is false
(d)A is false but R is true
Q: With reference to ionic compounds, consider the following statements: 1. Ionic compounds are insoluble in alcohol. 2. Ionic compounds in the solid state are good conductors of electricity. Which of these statements is/are correct?
(a)Only 1
(b)Only 2
(c)Both 1 and 2
(d)Neither 1 nor 2
Q: Which one of the following statements is correct?
(a)The presence of NaCl increases the rate of setting of Plaster of Paris
(b)Gypsum is added to the cement to slow down its rate of setting
(c)All alkaline earth metals form hydrated salts
(d)Barium and Strontium are found free in nature
Q: Assertion (A): With the increase of temperature, the viscosity of glycerine increases. Reason (R): Rise of temperature increases kinetic energy of molecules.
(a)Both A and R are individually true and R is the correct explanation of A
(b)Both A and R are individually true but R is not a correct explanation of A
(c)A is true but R is false
(d)A is false but R is true
Q: Assertion (A): Synthetic detergents can lather well in hard water. Reason (R): Synthetic detergents form soluble calcium and magnesium salts with hard water.
(a)Both A and R are individually true and R is the correct explanation of A
(b)Both A and R are individually true but R is not a correct explanation of A
(c)A is true but R is false
(d)A is false but R is true
Q: Assertion (A): A chemical reaction becomes faster at higher temperatures. Reason (R): At higher temperatures, molecular motion becomes more rapid. Which of the following is correct?
(a)Both A and R are individually true and R is the correct explanation of A
(b)Both A and R are individually true but R is NOT a correct explanation of A
(c)A is true but R is false
(d)A is false but R is true
Q: Which one of the following is the correct sequence in increasing order of molecular weights of the hydrocarbons?
(a)Methane, ethane, propane and butane
(b)Propane, butane, ethane and methane
(c)Butane, ethane, propane and methane
(d)Butane, propane, ethane and methane
Q: In an atom, the order of filling up of the orbitals is governed by
(a)Aufbau principle
(b)Heisenberg’s uncertainty principle
(c)Hund’s rule
(d)Pauli’s exclusion principle
Q: An aqueous solution of copper sulphate is acidic in nature because the salt undergoes
(a)dialysis
(b)electrolysis
(c)hydrolysis
(d)photolysis
Q: Consider the following statements with reference to the Periodic Table of chemical elements: I. Ionisation potential gradually decreases along a period. II. In a group of elements, electron affinity decreases as the atomic weight increases. III. In a given period, electronegativity decreases as the atomic number increases. Which of these statement(s) is/are correct?
(a)I only
(b)II only
(c)I and III
(d)II and III
Q: Match List I with List II and select the correct answer using the codes given below the Lists: List I I. German Silver II. Solder III. Bleaching Powder IV. Hypo List II A) Tin B) Nickel C) Sodium D) Chlorine Codes:
(a)I-A, II-B, III-D, IV-C
(b)I-B, II-A, III-C, IV-D
(c)I-A, II-B, III-C, IV-D
(d)I-B, II-A, III-D, IV-C
Q: A small pouch containing silica gel is often found in bottles of medicine in tablet or powder form because silica gel
(a)kills bacteria
(b)kills germs and spores
(c)absorbs moisture
(d)absorbs all gases present inside the bottle
Q: Match List I (Industrial processes) with List II (Industry with which associated) and select the correct answer using the codes given below the Lists: List I I. Cracking II. Smelting III. Hydrogenation IV. Vulcanization List II A) Rubber B) Petroleum C) Copper D) Edible fats Codes:
(a)I-C, II-B, III-A, IV-D
(b)I-B, II-C, III-D, IV-A
(c)I-B, II-C, III-A, IV-D
(d)I-C, II-B, III-D, IV-A
Q: Consider the following statements: Hard water is not suitable for I. drinking. II. washing clothes with soap. III. use in boilers. IV. irrigating crops. Which of these statements are correct?
(a)I and III
(b)II and III
(c)I, II and IV
(d)I, II, III and IV
Q: Assertion (A): To dilute sulphuric acid, acid is added to water and not water to acid. Reason (R): Specific heat of water is quite large.
(a)Both A and R are true, and R is the correct explanation of A
(b)Both A and R are true, but R is not a correct explanation of A
(c)A is true, but R is false
(d)A is false, but R is true
Q: Match List I with List II and select the correct answer using the codes given below the lists: List I I. Potassium bromide II. Potassium nitrate III. Potassium sulphate IV. Mono-potassium tartrate List II A. Fertiliser B. Photography C. Bakery D. Gunpowder Codes:
(a)I-B, II-D, III-A, IV-C
(b)I-B, II-D, III-C, IV-A
(c)I-D, II-B, III-C, IV-A
(d)I-D, II-B, III-A, IV-C
Q: Which one of the following metals does not form amalgams?
(a)Zinc
(b)Copper
(c)Magnesium
(d)Iron
Q: Consider the following statements about acetylene: I. It is used in welding industry. II. It is raw material for preparing plastics. III. It is easily obtained by mixing silicon carbide and water. Of these statements:
(a)I and II are correct
(b)I and III are correct
(c)II and III are correct
(d)I, II and III are correct
Q: Match List I with List II and select the correct answer using the codes given below the lists: List I I. Blue vitriol II. Epsom salt III. Baking soda IV. Caustic soda List II A) Sodium bicarbonate B) Sodium hydroxide C) Magnesium sulphate D) Copper sulphate
(a)I-C, II-D, III-B, IV-A
(b)I-D, II-C, III-A, IV-B
(c)I-C, II-D, III-A, IV-B
(d)I-D, II-A, III-B, IV-A
Q: Assertion (A): Formic acid is a stronger acid than acetic acid. Reason (R): Formic acid is an organic acid.
(a)Both A and R are true, and R is the correct explanation of A
(b)Both A and R are true, but R is NOT a correct explanation of A
(c)A is true, but R is false
(d)A is false, but R is true
Q: Assertion (A): Phenyl is used as a household germicide. Reason (R): Phenyl is a phenol derivative and phenol is an effective germicide.
(a)Both A and R are true, and R is the correct explanation of A
(b)Both A and R are true, but R is NOT a correct explanation of A
(c)A is true, but R is false
(d)A is false, but R is true
Q: Assertion (A): Sodium metal is stored under kerosene. Reason (R): Metallic sodium melts when exposed to air.
(a)Both A and R are true, and R is the correct explanation of A
(b)Both A and R are true, but R is NOT a correct explanation of A
(c)A is true, but R is false
(d)A is false, but R is true
Q: Which one of the following was used as a chemical weapon in the First World War?
(a)Carbon monoxide
(b)Hydrogen cyanide
(c)Mustard gas
(d)Water gas
Q: Which one of the following is present in the largest amount in terms of per cent by mass in the earth’s crust?
(a)Silicon
(b)Oxygen
(c)Carbon
(d)Calcium
Q: The characteristic odour of garlic is due to
(a)a chloro compound
(b)a sulphur compound
(c)a fluorine compound
(d)acetic acid
Q: Which one of the following is an active component of oil of clove?
(a)Menthol
(b)Eugenol
(c)Methanol
(d)Benzaldehyde
Q: The most reactive among the halogens is
(a)fluorine
(b)chlorine
(c)bromine
(d)iodine
Q: Which one of the following is paramagnetic in nature?
(a)Iron
(b)Hydrogen
(c)Oxygen
(d)Nitrogen
Q: Which one of the following is used as an anti-freeze for the automobile engines?
(a)Propyl alcohol
(b)Ethanol
(c)Methanol
(d)Ethylene glycol
Q: 101. Which one of the following is a mixed fertilizer?
(a)CAM
(b)Urea
(c)Ammonium Sulphate
(d)NPK
Q: 103. The chemical used as a ‘fixer’ in photography is
(a)sodium sulphate
(b)sodium thiosulphate
(c)ammonium persulphate
(d)borax
Frequently Asked Questions
How many UPSC Prelims questions have been asked from Chemistry?▼
UPSC has asked 51 questions on Chemistry in GS Paper 1 Prelims between 1995 and 2021. This sub-topic falls under Science & Technology.
In which years has UPSC asked about Chemistry?▼
Questions on Chemistry have appeared in UPSC Prelims in the following years: 2021, 2019, 2014, 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002, 2001, 2000, 1999, 1998, 1997, 1995. The topic has appeared in 18 out of 31 years.
What is the difficulty level of Chemistry questions in UPSC Prelims?▼
Among 51 questions on Chemistry: 36 are easy, 15 are moderate, and 0 are difficult. Most questions test conceptual understanding of the topic.