Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. Which among the following are constituents of Brass?
[A] Zinc and Copper
[B] Iron and Zinc
[C] Copper and Nickel
[D] Iron and Copper
Show Answer
Correct Answer: A [Zinc and Copper ]
Notes:
Brass is an alloy of Copper and Zinc, in proportions which can be varied to achieve varying mechanical and electrical properties. The proportions of Zinc and Copper can vary to create different types of brass alloys with varying mechanical and electrical properties.
2. Which of the following type of Coal has maximum carbon content?
[A] Peat
[B] Lignite
[C] Antharacite
[D] Bituminious
Show Answer
Correct Answer: C [Antharacite]
Notes:
Anthracite, often referred to as hard coal, is a hard, compact variety of coal that has a submetallic luster. It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal and is the highest ranking of coals.
3. What is the primary event that occurs during an oxidation reaction?
[A] Electrons are gained
[B] Electrons are lost
[C] Protons are gained
[D] Protons are lost
Show Answer
Correct Answer: B [Electrons are lost]
Notes:
Oxidation is a chemical reaction in which an atom, ion, or molecule loses an electron to another substance. So, the correct answer is “Electrons are lost”. This phenomenon is often observed in various chemical and biological systems. Understanding this important process can allow us to gain insights in fields ranging from biology to materials science.
4. What is the electrical state of a molecule, considered the smallest part of matter retaining the properties of the original matter?
[A] Positive
[B] Negative
[C] Either positive or negative
[D] Neutral
Show Answer
Correct Answer: D [Neutral]
Notes:
A molecule represents the smallest portion of a substance that retains the characteristics of the substance. It’s electrically neutral because it’s made up of atoms that bond together, sharing or exchanging electrons to achieve stability. This process balances out the electrical charges of the protons and electrons, rendering the molecule as a whole electrically neutral.
5. Charles Goodyear is known for which of the following ?
[A] Experiments on Rubber Plants
[B] Vulcanization of Rubber
[C] Invention of Radial Tyres
[D] Invention of Artificial Rubber
Show Answer
Correct Answer: B [Vulcanization of Rubber]
Notes:
Charles Goodyear, American inventor of the vulcanization process that made possible the commercial use of rubber. The Goodyear Tire and Rubber Company was posthumously named after him.
6. Which of these is not considered an ore?
[A] Chalcopyrite
[B] Sphalerite
[C] Cinnabar
[D] Andesite
Show Answer
Correct Answer: D [Andesite]
Notes:
Andesite is an igneous volcanic rock with intermediate composition and is not used as an ore. Chalcopyrite is a major copper ore, sphalerite is the primary ore of zinc, and cinnabar is the main ore of mercury. Andesite mainly consists of plagioclase, pyroxene, and amphibole minerals and forms in volcanic arcs associated with subduction zones.
7. Consider the following:
- Hydrogen (H2)
- Carbon monoxide (CO)
- Carbon dioxide (CO2)
- Methane (CH4)
Which of the above is/are component(s) of high-quality (100% pure) Syngas?
[A] 1 Only
[B] 1 & 2 Only
[C] 1, 2 & 3 Only
[D] 1, 2, 3 & 4
Show Answer
Correct Answer: B [ 1 & 2 Only]
Notes:
The high-quality (100% Pure) Syngas has the main components of (H2 + CO)
8. Which of the following is NOT correct about Ethanol?
[A] It is a good solvent
[B] It gives out hydrogen when reacted with Sodium
[C] It is an odorless liquid
[D] All are correct
Show Answer
Correct Answer: C [It is an odorless liquid]
Notes:
Ethanol is a good solvent and reacts with sodium leading to the evolution of hydrogen. It is a colorless liquid with a slight characteristic odor.
9. What is the relationship between becquerel and curie unit?
[A] 1 curie = 0.5 Bq
[B] 1 curie = 9 × 106 Bq
[C] 1 curie = 3.7 × 1010 Bq
[D] 1 curie = 5.7 Bq
Show Answer
Correct Answer: C [1 curie = 3.7 × 1010 Bq]
Notes:
1 curie = 1 Ci = 3.7 × 1010 decays per second = 3.7 × 1010 Bq. This is approximately the amount of radioactivity emitted by one gram (1 g) of radium-226. The ‘curie’ unit is named after Pierre Curie, a French physicist.
10. What do we call the reactions in which there is an exchange of ions between the reactants?
[A] Double Displacement reaction
[B] Decomposition reaction
[C] Displacement reaction
[D] Combination reaction
Show Answer
Correct Answer: A [Double Displacement reaction]
Notes:
The reactions in which there is an exchange of ions between the reactants are called double displacement reactions.
