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 is popularly called Hypo?
[A] Silver Bromide
[B] Silver nitrate
[C] Sodium thiosulphate
[D] Sodium phosphate
Show Answer
Correct Answer: C [Sodium thiosulphate ]
Notes:
Sodium thiosulfate is an important inorganic salt with several medical uses. It is also called sodium hyposulfite or ‘hypo’. It is used in several pharmaceutical preparations and also has various medical properties.
2. What are the main constituents of LPG?
[A] Methane, Hexane, Ethane
[B] Methane, Butane, Propane
[C] Ethane, Pentane, Hexane
[D] Ethane, Methane, Pentane
Show Answer
Correct Answer: B [Methane, Butane, Propane]
Notes:
LPG is composed hydrocarbons containing three or four carbon atoms. The normal components of LPG thus, are propane (C3H8), butane (C4H10) and Methane (CH4). Small concentrations of other hydrocarbons may also be present.
3. Which of the following is the correct term used to describe Graphite, Carbon and Diamonds?
[A] Isotopes
[B] Isomers
[C] Isotones
[D] Allotropes
Show Answer
Correct Answer: D [Allotropes]
Notes:
Allotropes refer to two or more different physical forms in which an element can exist. The property is due to different ways atoms bond together. The most common instance is the element carbon, which exists in several different forms, including diamond, graphite, and fullerenes, making it an allotropic element. It’s crucial to note that allotropy applies to elements, not compounds.
4. The primary part of Liquefied Petroleum Gas LPG is ______?
[A] Butane
[B] Methane
[C] Propane
[D] Butane or Propane
Show Answer
Correct Answer: D [Butane or Propane]
Notes:
LPG consists mainly of propane, propylene, butane, and butylene in various mixtures. The primary gas can be either Propane or Butane.
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 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.
7. Which of the following chemicals is resposible for temporary acid rain in colder regions?
[A] Hydrogen chloride
[B] Sulphur dioxide
[C] Nitric acid
[D] Nitrogen oxides
Show Answer
Correct Answer: A [ Hydrogen chloride]
Notes:
Hydrogen chloride gas released from volcanic eruption is responsible for temporary acid rain in colder regions.
8. Which of the following is correct about Ammonia?
[A] The ammonia molecule is trigonal pyramidal in shape
[B] Ammonia gas is light blue in colour
[C] its aqueous solution is highly basic
[D] Ammonia gas is odorless
Show Answer
Correct Answer: A [The ammonia molecule is trigonal pyramidal in shape]
Notes:
Ammonia is a colourless gas with a pungent odour. Its aqueous solution is weakly basic due to the formation of OH– ions. The ammonia molecule is trigonal pyramidal in shape.
9. Which of the following is correct?
[A] A colloidal solution is a heterogeneous mixture
[B] A colloidal solution is a homogeneous mixture
[C] The particles of a colloidal solution cannot scatter beam of light
[D] None of the above
Show Answer
Correct Answer: A [A colloidal solution is a heterogeneous mixture]
Notes:
Due to the relatively smaller size of particles, as compared to that of a suspension, the mixture appears to be homogeneous. But actually, a colloidal solution is a heterogeneous mixture. The particles can easily scatter a beam of visible light.
10. Which of the following refining methods works on the principle that impurities are more soluble in the melt than in the solid state of the metal?
[A] Liquation
[B] Electrolytic refining
[C] Zone refining
[D] Vapour Phase refining
Show Answer
Correct Answer: C [Zone refining]
Notes:
Zone refining works on the principle that impurities are more soluble in the melt than in the solid state of the metal. This method is very useful for producing semiconductors.
