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. These questions are part of GKToday’s 35000+ MCQs Bank Course in GKToday Android App
11. Which of the following hydrogen bond is formed in the case of o-nitrophenol?
[A] Intramolecular
[B] Intermolecular
[C] Both a and b
[D] None
Show Answer
Correct Answer: B [Intermolecular]
Notes:
Intermolecular Hydrogen bond is formed when hydrogen atom is in between the two highly electronegative atoms present within the same molecule. For example: hydrogen is in between two Oxygen atom in the case of o-nitrophenol.
12. Which of these is a biodegradable polymer?
[A] PLA
[B] PCL
[C] PGA
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
A large number of bio degradable polymers are now available will replace non-bio-degradable polymers as their cost reduces. Some of the important biodegradable polymers are PHBV, PGA, PLA and PCL.
13. Which of these polymers is formed by the polymerization of the dimer of lactic acid?
[A] PLA
[B] PCL
[C] PGA
[D] None of the above
Show Answer
Correct Answer: A [PLA]
Notes:
PLA, also known as Polyactic acid, is obtained by polymerization of the dimer of lactic acid. It is also produced by micro biological synthesis of lactic acid followed by the polycondensation and removal of water by evaporation.
14. Which of the following is not a property of Nylon-66?
[A] Nylon fibres have low tensile strength
[B] Nylon fibres are resistant to abrasion
[C] Nylon fibres are somewhat elastic in nature
[D] All of the above
Show Answer
Correct Answer: A [Nylon fibres have low tensile strength]
Notes:
Nylon fibres have high tensile strength. They are tough and resistant to abrasion. They are also somewhat elastic in nature.
15. Which of the following carbon compound is used in the polymerisation process to produce polythene?
[A] Methane
[B] Ethene
[C] Ethyne
[D] Benzene
Show Answer
Correct Answer: B [Ethene]
Notes:
Ethene is used in the polymerisation process to produce polythene. The process of formation of polymers from respective monomers is called polymerisation.
16. Which of these non-metals are present in Gun powder?
[A] Sulphur
[B] Carbon
[C] Nitrogen
[D] All of the above
Show Answer
Correct Answer: D [ All of the above ]
Notes:
Carbon, Nitrogen and Sulphur are the non-metals present in the Gun powder. It is a mixture of potassium nitrate, sulphur and charcoal.
17. What are the structures formed by the soap molecules, during cleansing, known as?
[A] Stereates
[B] Esters
[C] Micelles
[D] Tubes
Show Answer
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.
18. Which of the following metals is the first metal used by a man?
[A] Gold
[B] Copper
[C] Silver
[D] Iron
Show Answer
Correct Answer: B [Copper]
Notes:
A copper awl is the oldest metal object unearthed to date in the Middle East. The discovery reveals that metals were exchanged across hundreds of miles in this region more than 6,000 years ago, centuries earlier than previously thought, researchers say.
19. Which gas is called the “firedamp” in coal mines?
[A] Hydrogen
[B] Carbon monoxide
[C] Air
[D] Methane
Show Answer
Correct Answer: D [Methane]
Notes:
Firedamp is flammable gas found in coal mines. It is the name given to a number of flammable gases, especially methane. Firedamp is a gas that occurs naturally in coal seams. Firedamp gas is nearly always methane (CH4) and is highly inflammable and explosive when present in the air in a proportion of 5 to 14 per cent. Fire-damp has always been a source of terror for miners in coal districts. It is formed from the initial biological matter during geological processes in the course of carbonization. Fire-damp has a somewhat different composition than natural gas accompanying oil, therefore it is sometimes called “carboniferous natural gas”.
20. Which of the following causes the rusting of iron?
- Oxidation
- Reduction
- Chemical reaction with oxygen
- Chemical reaction with CO2
Select the correct answer from the codes given below:
[A] Only 1 and 2
[B] Only 2 and 3
[C] Only 3 and 4
[D] Only 1 and 3
Show Answer
Correct Answer: D [Only 1 and 3]
Notes:
Rust is composed of iron oxides. In colloquial usage, the term is applied to red oxides, formed by the reaction of iron and oxygen in the presence of water or air moisture. When impure (cast) iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts. If salt is present, for example in seawater or salt spray, the iron tends to rust more quickly, as a result of electrochemical reactions. Supporting the process of rusting.
