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 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
3. 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.
4. Which among the following kinds of glass is used generally in making of the Bullet proof screens?
[A] Pyrex glass
[B] Jena glass
[C] Reinforced Glass
[D] Flint Glass
Show Answer
Correct Answer: C [Reinforced Glass]
Notes:
Reinforced Glass or Toughened glass or tempered glass is a kind of safety glass is used as s a component of bulletproof glass, for diving masks, and various types of plates and cookware.
5. 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.
6. Duralumin which is used in making aero planes is an alloy consisting of _____?
[A] Aluminum & Copper
[B] Aluminum, Copper & Manganese
[C] Aluminum, Copper, Manganese & Magnesium
[D] Aluminum and zinc
Show Answer
Correct Answer: C [Aluminum, Copper, Manganese & Magnesium]
Notes:
Duralumin is an alloy primarily composed of aluminum, copper, manganese, and magnesium. It was developed in the early 20th century and is known for its high strength-to-weight ratio, making it ideal for aircraft construction. The addition of copper enhances strength, while manganese and magnesium improve corrosion resistance and workability. Duralumin was first used in aircraft during World War I, revolutionizing aviation materials.
7. Which among the following basic atoms are must in an Alkaloid?
[A] Sodium
[B] Nitrogen
[C] Magnesium
[D] Potassium
Show Answer
Correct Answer: B [Nitrogen]
Notes:
Alkaloids are a class of naturally occurring organic compounds that mostly contain basic nitrogen atoms. Nitrogen is essential in their structure, contributing to their pharmacological properties. Common examples of alkaloids include morphine, caffeine, and nicotine, all of which contain nitrogen. Sodium, magnesium, and potassium are not fundamental components of alkaloids.
8. 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.
9. PAN (Peroxyacetyl nitrate) is a secondary gaseous compound found in _?
[A] Classical smog
[B] Volatile organic compound
[C] Photochemical smog
[D] Green manure
Show Answer
Correct Answer: C [ Photochemical smog]
Notes:
Third option is the correct answer
Photochemical smog is the chemical reaction of sunlight, nitrogen oxides and volatile organic compounds in the atmosphere, which leaves airborne particles and ground-level ozone.
10. Flint, which was used by the prehistoric man to make tools is a __?
[A] Igneous rock
[B] Sedimentary rock
[C] Metamorphic rock
[D] None of the above
Show Answer
Correct Answer: B [ Sedimentary rock]
Notes:
Flint is a sedimentary rock. It’s a type of microcrystalline quartz in the chert family. Flint is known for its sharp edges and ability to be easily flaked into various shapes. It was widely used by early humans to make a variety of tools, including: Knives, Scrapers, Points, Axe-heads, Hammers, Choppers. Flint is often found along streams and beaches. It’s close behind diamond in hardness and fractures easily to give razor sharp edges.