Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination. These questions are part of GKToday’s 35000+ MCQs Bank Course in GKToday Android App
1. Which among the following compound is most commonly used in the Photochromic lenses?
[A] Potassium Dichromate
[B] Silver Chloride
[C] Potassium ferrate
[D] Ferric Chloride
Show Answer
Correct Answer: B [Silver Chloride]
Notes:
Photochromatic or Photochromic glass acquires a darker shade when exposed to bright light and returns to its original lighter shade in dim light. This happens because silver halides (iodide or chloride) is added to this glass
2. Which among following is also known as white gold?
[A] Nickel
[B] Rhodium
[C] Platinum
[D] Palladium
Show Answer
Correct Answer: C [Platinum]
Notes:
Platinum is a naturally white metal. It doses not need to be alloyed for color. Due to its appearance as white, it is commonly known as White Gold.
3. 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.
4. Which of the following chemicals is also known as lachrymatory agent or lachrymator?
[A] Mustard Gas
[B] Tear gas
[C] Diborane
[D] Chlorine gas
Show Answer
Correct Answer: B [ Tear gas]
Notes:
Tear gas is also known as CS Gas. It acts as a lachrymatory agent. Tear gas irritate the mucous membrane of the eyes, nose, mouth and lungs, and causes tearing, coughing, burning and difficult breathing.
5. Which of the following laws states that the partial vapour pressure of each component of an ideal mixture of liquids is equal to the vapour pressure of the pure component multiplied by its mole fraction in the mixture?
[A] Raoult’s law
[B] Henry’s law
[C] Graham’s law
[D] Sievert’s law
Show Answer
Correct Answer: A [ Raoult’s law]
Notes:
Raoult’s law states that the partial vapour pressure of each component of an ideal mixture of liquids is equal to the vapour pressure of the pure component multiplied by its mole fraction in the mixture.
6. Which of these principles state that in the ground state of the atoms, the orbitals are filled in order of their increasing energies?
[A] Pauli’s exclusion principle
[B] Hund’s rule of multiplicity
[C] Afbau principle
[D] None of the above
Show Answer
Correct Answer: C [Afbau principle]
Notes:
Afbau principle governs the filling up of orbitals with electrons. It states that in the ground state of the atoms, the orbitals are filled in order of their increasing energies.
7. Which of these species are isoelectronic?
[A] Al+ , B–
[B] Mg+ , Cu–
[C] Na+ , Al–
[D] Na+ , F–
Show Answer
Correct Answer: D [Na+ , F–]
Notes:
Isoelectronic species are those species which have the same number of electrons. In the above case, both Na+ and F– have 10 electrons.
8. What do we call the ratio of number of fission produced by a given generation of neutrons to the number of fission of the preceding generation?
[A] Critical factor
[B] Energy factor
[C] Multiplication factor
[D] Moderation factor
Show Answer
Correct Answer: C [Multiplication factor]
Notes:
The multiplication factor is the ratio of number of fission produced by a given generation of neutrons to the number of fission of the preceding generation.
9. Which of the following is true about a water molecule?
[A] It has a bent-shaped structure
[B] The bond angle is 120°
[C] It is a non-polar solvent
[D] All of the above
Show Answer
Correct Answer: A [It has a bent-shaped structure]
Notes:
The water molecule has a bent-shaped structure. The bond angle is 104.5° and it is a polar solvent. Infact, water is known as a universal solvent.
10. Choose the correct statement:
[A] Water exists as liquid due to hydrogen bonding
[B] Hydrogen bond is a weak bond as compared to ionic bond
[C] Both a and b
[D] None of the above
Show Answer
Correct Answer: C [Both a and b]
Notes:
Hydrogen bond is a weak bond and is quite small as compared to the covalent bond. it is due to hydrogen bonding only that water exists as a liquid.
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