Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. 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.
2. Which among the following is Quick Silver?
[A] Aluminium
[B] Mercury
[C] Lead
[D] Zinc
Show Answer
Correct Answer: B [Mercury]
Notes:
Mercury is a chemical element with the symbol Hg and atomic number 80. The element is also known as quicksilver for its mobility. Mercury is one of the oldest and deadliest poisons, a highly toxic metal mined from a brilliant red ore.
3. What is the number of naturally occurring Halogens in the periodic table?
[A] 3
[B] 4
[C] 5
[D] 6
Show Answer
Correct Answer: C [5]
Notes:
fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At)
4. Which among the following is the main constituent of vegetable oil and animal fats?
[A] Glycogen
[B] Triglyceride
[C] Galactose
[D] Diglyceride
Show Answer
Correct Answer: B [Triglyceride]
Notes:
The main constituent of vegetable oil and animal fats is triglyceride. Triglycerides are composed of three fatty acids linked to a glycerol molecule. They are the most common type of fat found in the body and serve as a major energy source. In fact, triglycerides account for about 95% of the fats in the human diet.
5. 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.
6. Acid rain is capable of damaging the buildings and historic monuments which are made up of rocks such as limestone and marble. Which among the following is the end product of such reaction?
[A] Quick Lime
[B] Calcium Carbonate
[C] Calcium Hydroxide
[D] Gypsum
Show Answer
Correct Answer: D [Gypsum]
Notes:
When sulfuric, and nitric acids, present in the acid rain reacts with the calcite in marble and limestone, it get dissolve and formed gypsum and washed off by the water. The rain can dissolve limestone and marble through direct contact.
7. Which of the following compound of sodium is generally prepared by Solvay process?
[A] Sodium Carbonate
[B] Sodium Hydroxide
[C] Sodium Chloride
[D] All of the above
Show Answer
Correct Answer: A [Sodium Carbonate]
Notes:
Sodium carbonate is generally prepared by Solvay Process.
8. Which among the following is most advantageous in storage in fuel cells used in small, portable electronics such as phones and laptop computers?
[A] Methanol
[B] Hydrogen
[C] Formic Acid
[D] Acetic Acid
Show Answer
Correct Answer: C [Formic Acid]
Notes:
The cells are called Direct-formic acid fuel cells, in which formic acid is directly fed in the cells. Storage of formic acid is much easier and safer than that of hydrogen because it does not need to be done at high pressures and (or) low temperatures, as formic acid is a liquid at standard temperature and pressure. Formic acid does not cross over the polymer membrane, so its efficiency can be higher than that of methanol. Use of acetic acid in cells does not arise.
9. Bell metal is an alloy of which of the following metals?
[A] Copper and Tin
[B] Copper and Mercury
[C] Copper and Lead
[D] Copper and Zinc
Show Answer
Correct Answer: A [Copper and Tin]
Notes:
Bell metal is a form of bronze with a higher tin content. It is an alloy of copper and tin (typically, 78% copper, 22% tin by mass). It is used for making bells and related instruments, such as cymbals.
10. Hydraulic Washing:
- is used for concentration of ores
- is based on differences in magnetic properties of the ore components
Which of the above is / are correct?
[A] Only 1
[B] Only 2
[C] Both 1 & 2
[D] Neither 1 nor 2
Show Answer
Correct Answer: A [Only 1 ]
Notes:
Hydraulic Washing is a method used for concentration of ores. It is a type of gravity separation as it is based on the differences in gravities of the ore and the gangue particles.