Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. 2,4-D, which is sold as a weed killer of the broad-leaved weeds is a synthetic version of __:
[A] Auxin Hormone
[B] Cytokinin Hormone
[C] Xylitol
[D] None of them
Show Answer
Correct Answer: A [Auxin Hormone ]
Notes:
2,4-dichlorophenoxyacetic acid (2,4-dichlorophenoxyethanoic acid) is a synthetic auxin frequently used as a weed killer of broad-leaved weeds. When two herbicides 2,4,5-T and 2,4-D and mixed in equal parts, it is called Agent Orange, which was used by US in Vietnam war.
2. Which among the following substances is most suitable for making Compact Discs?
[A] PVC
[B] Polyethylene
[C] Polyamides
[D] Polycarbonates
Show Answer
Correct Answer: D [Polycarbonates
]
Notes:
Polycarbonate(PC) is a tough thermoplastic. It is not only highly transparent but also has good toughness which most of the other thermoplastics do not possess. For this reason, it is widely used for making CDs, Safety Goggles, Mixer jar lids etc.
3. Kazimierz Funk or Casimir Funk, was a Polish biochemist, generally credited with the first formulation of the concept of which of the following ?
[A] Amino Acids
[B] DNA
[C] RNA
[D] Vitamins
Show Answer
Correct Answer: D [Vitamins]
Notes:
Kazimierz Funk (1884 – 1967) was a Polish biochemist, and one of the first to formulate the concept of Vitamins.
4. What is the atomic number of Transuranic elements?
[A] Greater than 90
[B] Greater than 92
[C] Greater than 91
[D] Greater than 93
Show Answer
Correct Answer: B [Greater than 92]
Notes:
Transuranic elements are those with atomic numbers greater than 92, which is the atomic number of uranium. These elements, including plutonium (94) and americium (95), are all synthetic and typically unstable, often used in nuclear applications and research. The term “transuranic” specifically refers to elements beyond uranium in the periodic table.
5. Which among the following minerals is also known as Horn Silver?
[A] Silver Iodide
[B] Silver Chroride
[C] Zinc Phosphate
[D] Silver Sulphide
Show Answer
Correct Answer: B [Silver Chroride]
Notes:
Chlorargyrite is the mineral form of silver chloride (AgCl). It is also known as cerargyrite and, when weathered by desert air, as horn silver. Silver chloride is formed by the disappearance of the initial silver oxide layer.
6. Which among the following alkane has largely replaced the ozone layer-depleting halomethanes in household refrigerators and freezers?
[A] Methane
[B] Propane
[C] Butane
[D] Ethane
Show Answer
Correct Answer: C [Butane]
Notes:
Isobutane, which is known in the industry as R600A has been used in several domestic refrigerators in recent times because it is an excellent refrigerant and non-ozone depleting substance with low global warming potential. The only drawback is that it is highly inflammable.
7. Which of the following occurs as dry deposits and is also known as Sajimati (efflorescent soil) in India?
[A] Sodium carbonate
[B] Potassium carbonate
[C] Calcium carbonate
[D] Magnesium carbonate
Show Answer
Correct Answer: A [ Sodium carbonate]
Notes:
Sodium carbonate is found as dry deposits and is also known as Sajimati (efflorescent soil) in India.
8. Choose the incorrect pair?
[A] Washing soda – Sodium Carbonate
[B] Caustic soda – Sodium Hydrogencarbonate
[C] Acetic acid – Ethanoic acid
[D] Bleaching powder – Calcium oxide
Show Answer
Correct Answer: D [Bleaching powder – Calcium oxide]
Notes:
Sodium carbonate is commonly known as Washing soda. Sodium Hydrogencarbonate is commonly known as Caustic soda. Ethanoic acid is commonly known as Acetic acid. calcium oxychloride is commonly known Bleaching powder.
9. Which of the following is correct about Solder?
[A] It is an alloy of lead and tin
[B] It is used for welding electrical wires together
[C] It has a low melting point
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Solder is an alloy of lead and tin (Pb and Sn). It has a low melting point and is used for welding electrical wires together.
10. Which of the following is not an ore of Zinc?
[A] Sphalerite
[B] Zincite
[C] Calamine
[D] Carnetite
Show Answer
Correct Answer: D [Carnetite]
Notes:
Carnetite is an ore of Uranium, where as Sphalerite(Zinc blende), Zincite and Calamine are some of the important ores of Zinc.
