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 is the key element used in the batteries of electric vehicles?
[A] Magnesium
[B] Lithium
[C] Sodium
[D] Bromine
Show Answer
Correct Answer: B [Lithium]
Notes:
The primary component for electric vehicle batteries is Lithium, used as Lithium carbonate or Lithium hydroxide. These Lithium-ion batteries have a high power-to-weight ratio, energy efficiency, and thermal stability, leading to their prevalence in electric vehicles. Notably, the boom in EVs has significantly driven the demand for Lithium globally.
2. Which among the following is the objective of the Methyl tert-butyl ether (MTBE) mixing with Petroleum?
[A] Raise Octane Number
[B] Antioxidant Stabilizer
[C] Lead Scavanger
[D] Fuel Dye
Show Answer
Correct Answer: A [Raise Octane Number ]
Notes:
MTBE is a gasoline additive, used as an oxygenate to raise the octane number. Its use is controversial in the US and declining in that country in part because of its occurrence in groundwater and legislation favoring ethanol.
3. Galena & Litharge are ores of which of the following metals?
[A] Mercury
[B] Zinc
[C] Copper
[D] Lead
Show Answer
Correct Answer: D [Lead]
Notes:
Galena and litharge are ores of lead. Galena is the most common ore of lead. It is the natural mineral form of lead (II) sulphid. Litharge is a secondary mineral that forms from the oxidation of galena ores. It is one of the natural mineral forms of Lead(II) oxide.
4. Which among the following groups is characteristic to alcohols?
[A] OH group
[B] COOH group
[C] COO group
[D] CO group
Show Answer
Correct Answer: A [OH group]
Notes:
Alcohols are organic compounds characterized by the presence of a hydroxyl group, denoted as -OH. This group consists of one oxygen atom bonded to a hydrogen atom. Due to the presence of the hydroxyl group, alcohols exhibit unique properties, such as the ability to form hydrogen bonds, making them polar. Alcohols are distinct from carboxylic acids (COOH), carbonates (COO), and carbonyl group compounds (CO).
5. What type of fiber is Rayon considered?
[A] A synthetic fiber
[B] A natural fiber
[C] A semi-synthetic fiber
[D] A synthetic detergent
Show Answer
Correct Answer: C [A semi-synthetic fiber]
Notes:
Rayon is considered a semi-synthetic fiber. It is made by regenerating natural materials into a usable form. Rayon fibers are derived from cellulose obtained from wood or related agricultural products. It was first commercially produced in 1905 by the Swiss firm J. R. Geigy, originally under the name “artificial silk”
6. 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.
7. What term refers to the minimum temperature at which a combustible substance begins to ignite?
[A] Fireless Temperature
[B] Ignition Temperature
[C] Static Temperature
[D] Optimum Temperature
Show Answer
Correct Answer: B [Ignition Temperature]
Notes:
The term for the minimum temperature necessary to ignite a combustible substance is “Ignition Temperature”. It plays a critical role in fire safety and in the field of thermodynamics. Incorrect handling of substances with low ignition temperatures can lead to hazardous situations like unexpected fires or explosions. Additionally, understanding a material’s ignition temperature helps in proper storage and safe handling to prevent unwanted accidents.
8. If a baby diaper is subjected to different solutions, which of the following will it absorb the maximum quantity of?
[A] Distilled Water
[B] Drinking Water
[C] Hard Water
[D] Urine
Show Answer
Correct Answer: A [Distilled Water]
Notes:
A baby diaper can absorb the maximum quantity of distilled water as it lacks impurities such as minerals and ions that are present in other type of water. The absorbent materials in diapers, often polymers called sodium polyacrylate, can hold up to 30 times their weight in distilled water, making them highly efficient.
9. Which among the following alkane has largely replaced the ozone layer-depleting halomethanes in household refrigerators and freezers?
[A] Methane
[B] Propane
[C] Butane
[D] Ethane
Show Answer
Correct Answer: C [Butane]
Notes:
Isobutane, which is known in the industry as R600A has been used in several domestic refrigerators in recent times because it is an excellent refrigerant and non-ozone depleting substance with low global warming potential. The only drawback is that it is highly inflammable.
10. The Potassium graphite and Calcium Graphite can be mostly used as which among the following?
[A] Moderators
[B] Semiconductors
[C] Superconductors
[D] Lubricants
Show Answer
Correct Answer: C [Superconductors]
Notes:
Potassium graphite and calcium graphite are primarily used as superconductors. Superconductors are materials that can conduct electricity without resistance when cooled below a certain temperature. Graphite, particularly when doped with potassium or calcium, exhibits enhanced superconducting properties. Notably, the discovery of high-temperature superconductors in the 1980s revolutionized the field, leading to applications in magnetic levitation and advanced electronic devices.