Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. Presence of which among the following minerals in Banana makes them slightly radioactive?
[A] Sodium
[B] Calcium
[C] Magnesium
[D] Pottasium
Show Answer
Correct Answer: D [Pottasium]
Notes:
Bananas contain potassium-40, a radioactive isotope of potassium, which makes them slightly radioactive. The radiation is very minor and not dangerous at all to humans, but it is enough to trigger sensitive radiation sensors. The potassium provides bananas some of their nutritional benefits as well.
2. Which among the following elements are generally find in free state?
[A] Group 11 elements
[B] Group 12 elements
[C] Group 13 elements
[D] Group 14 elements
Show Answer
Correct Answer: A [Group 11 elements ]
Notes:
Group 11 is also known as the coinage metals, due to their former usage. They were most likely the first three elements discovered. Copper, silver, and gold all occur naturally in elemental form.
3. Trimethylxanthine is a chemical name of a stimulant which is found in tea and coffee. What is the popular name?
[A] Thein
[B] Caffeine
[C] Theobromine
[D] Theophylline
Show Answer
Correct Answer: B [Caffeine]
Notes:
Caffeine (1, 3, 7-trimethylxanthine) also known as ancient wonder drug is a basically a neurostimulant easily available all over the world and is used in different products like tea, coffee, analgesic adjuvant, soft drinks and many dietary supplements.
4. Which acid is described as HOOCCOOH?
[A] Oxalic Acid
[B] Acetic Acid
[C] Carbonic Acid
[D] Citric Acid
Show Answer
Correct Answer: A [Oxalic Acid]
Notes:
Oxalic acid is an organic compound with the formula C₂H₂O₄. Some call it “crab acid” due to its appearance. Its condensed formula is HOOCCOOH, reflecting its classification as the simplest dicarboxylic acid.
5. What are the essential components used in the production of Nitrolim, a fertilizer extensively used in the past?
[A] Nitrogen & Limestone
[B] Calcium Carbide and Nitrogen
[C] Calcium Carbide & Carbon
[D] Calcium Carbide and Limestone
Show Answer
Correct Answer: B [Calcium Carbide and Nitrogen]
Notes:
Nitrolim is a type of fertilizer that was widely used in the past. The main components of Nitrolim are calcium carbide and nitrogen. Calcium carbide reacts with nitrogen to form calcium cyanamide, which is an active ingredient in Nitrolim. This fertilizer is significant as it helps in fixing nitrogen in the soil thereby promoting plant growth.
6. Which of the following statements about the chemical nature of Diamond and Graphite is incorrect?
[A] The density of Diamond is greater than that of Graphite
[B] Diamond is chemically unreactive whereas Graphite mildly reacts with certain elements
[C] Both Diamond and Graphite are excellent conductors of electricity
[D] None of the above statements is incorrect
Show Answer
Correct Answer: C [Both Diamond and Graphite are excellent conductors of electricity]
Notes:
Diamond and graphite are both forms of carbon but they exhibit different properties due to variations in their bonding arrangements. Diamond does not conduct electricity as each carbon atom in diamond is covalently bonded to four other carbon atoms, leaving no free electrons to conduct electricity. On the other hand, graphite is a good conductor of electricity due to its layered structure which leaves free electrons between the layers.
7. 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.
8. Which among the following makes Chile saltpetre different from saltpetre?
[A] Nitrate
[B] Sodium
[C] Magnesium
[D] Calcium
Show Answer
Correct Answer: B [Sodium]
Notes:
Chile saltpetre, or sodium nitrate (NaNO3), differs from regular saltpetre, which typically refers to potassium nitrate (KNO3). Chile saltpetre is primarily composed of sodium, while traditional saltpetre contains potassium. Historically, Chile saltpetre was extensively mined in the Atacama Desert and was crucial for fertilizer and explosives in the 19th century.
9. If a Hydrogen atom is removed from a hydrocarbon of Benzene group, the remaining residue is called _________?
[A] Alkyl
[B] Aryl
[C] Arene
[D] Azene
Show Answer
Correct Answer: B [Aryl]
Notes:
The correct answer is Aryl. In organic chemistry, when a hydrogen atom is removed from a benzene ring (a hydrocarbon), the remaining structure is referred to as an aryl group. Aryl groups are derived from aromatic compounds, specifically those containing a benzene ring. For example, when a hydrogen is removed from toluene (methylbenzene), the resulting aryl group is called a tolyl group. Aryl groups are important in various chemical reactions and are foundational in the synthesis of many organic compounds.
10. In the E-waste generated by the Mobile Phones, which among the following metal is most abundant?
[A] Copper
[B] Silver
[C] Palladium
[D] Gold
Show Answer
Correct Answer: A [Copper]
Notes:
The sources of e-waste are faulty desktop computers, cables, printers, refrigerators, air conditioners, televisions, electronic and electrical devices. E-waste generated by the Mobile Phones are copper, silver, gold, palladium. Among them copper is found abundantly.