MCQs on Chemistry

[Set - 6]

1. Which process is used to purify metal by using electrolysis?

A) Roasting
B) Smelting
C) Electrorefining
D) Leaching

Correct Answer: C) Electrorefining
Explanation: Electrorefining is a process that uses electrolysis to purify metals, such as copper. The impure metal is used as an anode, and a refined metal is deposited on the cathode.

2. Which process is primarily used for desalinating seawater?

A) Filtration
B) Reverse osmosis
C) Distillation
D) Coagulation

Correct Answer: B) Reverse osmosis
Explanation: Reverse osmosis is widely used for desalinating seawater. It involves forcing seawater through a semipermeable membrane that allows water molecules to pass but blocks salt and other impurities.

3. Which acid is commonly used for cleaning metal surfaces?

A) Sulfuric acid
B) Hydrochloric acid
C) Nitric acid
D) Acetic acid

Correct Answer: B) Hydrochloric acid
Explanation: Hydrochloric acid (muriatic acid) is commonly used for cleaning metal surfaces as it effectively removes rust and scale, preparing the surfaces for further processing or finishing.

4. What is the effect of catalysts on a chemical reaction?

A) Increase the reaction rate
B) Decrease the reaction rate
C) Change the products of the reaction
D) Consume reactants faster

Correct Answer: A) Increase the reaction rate
Explanation: Catalysts increase the rate of a chemical reaction without being consumed in the reaction. They achieve this by providing an alternative reaction pathway with a lower activation energy.

5. Which acid is known as the 'King of Chemicals'?

A) Hydrochloric acid
B) Sulfuric acid
C) Nitric acid
D) Acetic acid

Correct Answer: B) Sulfuric acid
Explanation: Sulfuric acid is often referred to as the ‘King of Chemicals’ due to its numerous industrial applications, including in the manufacture of fertilizers, chemical synthesis, mineral processing, and oil refining.

6. What is the main product formed when quicklime (calcium oxide) reacts with water?

A) Calcium hydroxide
B) Calcium carbonate
C) Calcium chloride
D) Calcium sulfate

Correct Answer: A) Calcium hydroxide
Explanation: When quicklime (calcium oxide, CaO) reacts with water, it forms calcium hydroxide (Ca(OH)₂), also known as slaked lime, which is used in mortar and plaster.

7. Which metal is most commonly associated with the term 'fool's gold'?

A) Iron
B) Copper
C) Gold
D) Pyrite

Correct Answer: D) Pyrite
Explanation: Pyrite, or iron sulfide (FeS₂), is commonly known as ‘fool’s gold’ due to its metallic luster and pale brass-yellow hue, which can resemble gold to the untrained eye.

8. What is the process of converting a liquid to a gas below its boiling point known as?

A) Condensation
B) Evaporation
C) Sublimation
D) Deposition

Correct Answer: B) Evaporation
Explanation: Evaporation is the process of converting a liquid into a vapor state at a temperature below its boiling point, typically occurring at the surface of the liquid.

9. What property measures a fluid's resistance to flow?

A) Viscosity
B) Density
C) Pressure
D) Temperature

Correct Answer: A) Viscosity
Explanation: Viscosity is the measure of a fluid’s resistance to flow. It describes how thick or sticky the fluid is and how much it resists being deformed.

10. Which element, when added to glass, can make it bulletproof?

A) Lead
B) Silicon
C) Boron
D) Aluminium

Correct Answer: C) Boron
Explanation: Boron, when added to glass in the form of boron oxide, can increase its strength and make it bulletproof. This type of glass is commonly used in security applications.

11. What is the term used for a solution that cannot dissolve more solute at a given temperature?

A) Saturated
B) Unsaturated
C) Supersaturated
D) Concentrated

Correct Answer: A) Saturated
Explanation: A saturated solution refers to a solution that contains the maximum amount of solute that can be dissolved in it at a given temperature. Adding more solute to a saturated solution leads to undissolved excess.

12. Which law relates the pressure of a gas to its temperature and volume?

A) Boyle’s Law
B) Charles’s Law
C) Ideal Gas Law
D) Dalton’s Law

Correct Answer: C) Ideal Gas Law
Explanation: The Ideal Gas Law (PV=nRT) relates the pressure (P), volume (V), and temperature (T) of an ideal gas through the gas constant (R) and the amount of gas in moles (n).

13. The corrosion of iron is an example of which type of reaction?

A) Combustion
B) Oxidation
C) Reduction
D) Neutralization

Correct Answer: B) Oxidation
Explanation: The corrosion of iron, also known as rusting, is an oxidation reaction where iron reacts with oxygen and water to form iron oxide.

14. Which gas is evolved when dilute hydrochloric acid reacts with zinc metal?

A) Oxygen
B) Hydrogen
C) Nitrogen
D) Chlorine

Correct Answer: B) Hydrogen
Explanation: When zinc metal reacts with dilute hydrochloric acid, hydrogen gas is evolved as a product of the single displacement reaction.

15. Which type of chemical compound results from the reaction between an acid and a base?

A) Salt
B) Oxide
C) Hydroxide
D) Peroxide

Correct Answer: A) Salt
Explanation: The reaction between an acid and a base typically results in the formation of a salt and water. This type of reaction is known as neutralization.

16. What is the main process used to increase the concentration of ore minerals?

A) Smelting
B) Roasting
C) Leaching
D) Froth flotation

Correct Answer: D) Froth flotation
Explanation: Froth flotation is a process used to separate hydrophobic materials from hydrophilic materials. It is primarily used in the mining industry to increase the concentration of ore minerals.

17. Which element is essential for the construction of MRI machines due to its superconducting properties?

A) Iron
B) Copper
C) Niobium
D) Tungsten

Correct Answer: C) Niobium
Explanation: Niobium is used in the construction of MRI (Magnetic Resonance Imaging) machines due to its superconducting properties when alloyed with titanium or tin.

18. Which law describes the direct proportionality between the pressure and temperature of a gas at constant volume?

A) Charles’s Law
B) Boyle’s Law
C) Gay-Lussac’s Law
D) Avogadro’s Law

Correct Answer: C) Gay-Lussac’s Law
Explanation: Gay-Lussac’s Law states that the pressure of a given mass of gas varies directly with the absolute temperature when the volume is kept constant.

19. What is the primary function of antioxidants in food?

A) To increase nutritional value
B) To enhance flavor
C) To preserve freshness
D) To prevent oxidation

Correct Answer: D) To prevent oxidation
Explanation: Antioxidants are added to food to prevent oxidation, a chemical reaction that can cause the deterioration of food quality, including the rancidity of fats and oils.

20. Which isotope of uranium is commonly used in nuclear reactors?

A) Uranium-234
B) Uranium-235
C) Uranium-238
D) Uranium-239

Correct Answer: B) Uranium-235
Explanation: Uranium-235 is the isotope commonly used in nuclear reactors and nuclear weapons because of its ability to sustain a nuclear chain reaction.

Share this with your friends

Solve More MCQs on Chemistry

    •   Back
    • MCQs History
    • MCQs Geography
    • MCQs Polity
    • MCQs Economy
    • MCQs Physics
    • MCQs Chemistry
    • MCQs Biology
    • MCQs Art and Culture
    • MCQs Science and Technology
    • MCQs Environment and Ecology
    • MCQs Inventions and Discoveries
    • MCQs Awards and Honors
    • MCQs Important days and dates
    • MCQs Famous Personalities
Show All
Lorem Ipsum is simply dumy text of the printing typesetting industry lorem ipsum.

Subscribe to our Newsletter

Subscribe to our Newsletter

& stay ahead of your competitors!

You have been successfully Subscribed! Ops! Something went wrong, please try again.
Subscribe Form

* Subscribe to our email newsletter to get the latest posts delivered right to your email.

© MCQs 4 Exams. All rights reserved.