General Science Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination
71. Which of these is not a Linear polymer?
[A] Starch
[B] Polyethelene
[C] Nylons
[D] Polyesters
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Correct Answer: A [Starch]
Notes:
The polymers in which monomeric units are linked together to form linear chains are known as a linear polymer. Examples are polyethelene, nylons and polyesters.
72. Which of the following metals is the major constituent of Pewter alloy?
[A] Tin
[B] Indium
[C] Titanium
[D] Lead
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Correct Answer: A [Tin]
Notes:
Tin is the major constituent of Pewter alloy. It is traditionally composed of 85–99% tin, mixed with copper, antimony, bismuth.
73. Which of these non-metals is mainly used as an inert shielding gas?
[A] Xenon
[B] Hydrogen
[C] Argon
[D] Krypton
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Correct Answer: C [ Argon ]
Notes:
Argon is used mainly to provide an inert atmosphere in high temperature metallurgical processes (arc welding of metals or alloys). It is also used for filling electric bulbs.
74. Which of these elements is used as a dopant in n-type silicon wafers?
[A] Antimony
[B] Iodine
[C] Carbon
[D] Radon
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Correct Answer: A [ Antimony ]
Notes:
Antimony is used in semiconductors as a dopant in n-type silicon wafers for diodes, infrared detectors, and Hall-effect device. Antimony is a gray metalloid having atomic number 51.
75. What are the structures formed by the soap molecules, during cleansing, known as?
[A] Stereates
[B] Esters
[C] Micelles
[D] Tubes
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Correct Answer: C [Micelles]
Notes:
The ionic-end of soap dissolves in water while the carbon chain dissolves in oil. The soap molecules form structures called micelles where one end of the molecules is towards the oil droplet while the ionic-end faces outside.
76. Which of these salts is responsible for the hardness of water?
[A] Calcium
[B] Magnesium
[C] Sodium
[D] Both a and b
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Correct Answer: D [Both a and b]
Notes:
The water becomes hard when water percolates through deposits of limestone and chalk which are largely made up of calcium and magnesium salts.
77. Which of the following detergents represent the liquid dishwashing detergents?
[A] Anionic
[B] Cationic
[C] Non-ionic
[D] None of the above
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Correct Answer: C [Non-ionic]
Notes:
Liquid dishwashing detergents are of non-ionic type. Non-ionic detergents do not contain any ion in their constitution.
78. Which of these chemical is used to form soaps containing sodium salts?
[A] Sulphuric acid
[B] Sodium hydroxide
[C] Nitric acid
[D] Carbonic acid
Show Answer
Correct Answer: B [Sodium hydroxide]
Notes:
Soaps containing sodium salts are formed by heating fat with aqueous sodium hydroxide solution. This reaction is known as saponification.
79. Which of these drugs help to reduce or abolish pain without causing impairment of consciousness?
[A] Analgesics
[B] Antibiotics
[C] Tranquilisers
[D] Antiseptics
Show Answer
Correct Answer: A [ Analgesics]
Notes:
Analgesics reduce or abolish pain without causing impairment of consciousness, mental confusion, in coordination or paralysis or some other disturbances of nervous system.
80. Which of the following is the use of Aspirin drug?
[A] Reduces fever
[B] helps in skeletal pain
[C] helps in preventing heart attacks
[D] All of the above
Show Answer
Correct Answer: D [ All of the above]
Notes:
Aspirin is effective in relieving skeletal pain such as that due to arthritis and in reducing fever (antipyretic).Because of its anti blood clotting action, aspirin finds use in prevention of heart attacks.
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