MCQs on Chemistry

[Set - 8]

1. Which technique is used to measure the concentration of an unknown solution using a solution of known concentration?

A) Titration
B) Filtration
C) Distillation
D) Chromatography

Correct Answer: A) Titration
Explanation: Titration is a technique used in analytical chemistry to determine the concentration of an unknown solution by reacting it with a solution of known concentration, often using an indicator to detect the endpoint.

2. Which element is added to steel to improve its ability to harden when quenched?

A) Chromium
B) Manganese
C) Carbon
D) Tungsten

Correct Answer: C) Carbon
Explanation: Carbon is added to steel to improve its hardness and strength. Higher carbon content allows the steel to form martensite when quenched, which is a very hard form of steel.

3. What is the process called when a gas turns into a liquid?

A) Freezing
B) Melting
C) Condensation
D) Sublimation

Correct Answer: C) Condensation
Explanation: Condensation is the process in which a gas turns into a liquid. It occurs when a gas is cooled to a temperature below its dew point, or when the gas comes into contact with a cold surface.

4. What property of noble gases makes them useful in lighting and signage?

A) Low reactivity
B) High reactivity
C) Radioactivity
D) Photoreactivity

Correct Answer: A) Low reactivity
Explanation: The low reactivity of noble gases makes them ideal for use in lighting and signage. Their inertness allows them to glow distinctively when an electric current passes through them without undergoing chemical changes.

5. Which mineral is the primary source of aluminum?

A) Galena
B) Hematite
C) Bauxite
D) Sphalerite

Correct Answer: C) Bauxite
Explanation: Bauxite is the primary mineral source of aluminum. It is a naturally occurring ore containing aluminum hydroxide minerals, which are processed to extract aluminum metal.

6. Which gas is commonly used as a 'lifting gas' for balloons due to its low density?

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

Correct Answer: A) Helium
Explanation: Helium is used as a lifting gas for balloons and airships due to its low density compared to air. It is safer than hydrogen, which is also light but highly flammable.

7. What process is used to harden steel by heating and rapidly cooling it?

A) Annealing
B) Tempering
C) Quenching
D) Forging

Correct Answer: C) Quenching
Explanation: Quenching is a heat treatment process used to harden steel. The steel is heated to a high temperature and then rapidly cooled, typically in water or oil, which traps carbon within the structure, increasing hardness.

8. Which element is known for having the highest thermal conductivity?

A) Copper
B) Aluminum
C) Gold
D) Silver

Correct Answer: D) Silver
Explanation: Silver has the highest thermal conductivity of any metal, making it highly effective in applications requiring rapid heat dissipation, such as in heat exchangers and cooling systems.

9. Which law states that the total pressure exerted by a gaseous mixture is equal to the sum of the partial pressures of each individual component in the gas mixture?

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

Correct Answer: C) Dalton’s Law
Explanation: Dalton’s Law of Partial Pressures states that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of each component of the gas mixture.

10. Which type of crystalline solid has high melting points and is formed from positive and negative ions?

A) Metallic solids
B) Molecular solids
C) Covalent network solids
D) Ionic solids

Correct Answer: D) Ionic solids
Explanation: Ionic solids are composed of positive and negative ions held together by strong electrostatic forces, known as ionic bonds. These solids typically have high melting points.

11. What is the pH range of acids?

A) 0-7
B) 7-14
C) 0-14
D) None of the above

Correct Answer: A) 0-7
Explanation: Acids have a pH range from 0 to 7, with 0 being the most acidic, 7 being neutral, and values less than 7 indicating acidity.

12. What type of isomerism involves compounds with the same molecular formula but different arrangements of atoms in space?

A) Structural isomerism
B) Geometric isomerism
C) Conformational isomerism
D) Optical isomerism

Correct Answer: B) Geometric isomerism
Explanation: Geometric isomerism (or cis-trans isomerism) involves compounds that have the same molecular formula but differ in the spatial arrangement of atoms around a double bond or a ring structure, resulting in different physical and chemical properties.

13. Which compound is typically used as an antifreeze in automobile radiators?

A) Ethylene glycol
B) Methanol
C) Propanol
D) Ethanol

Correct Answer: A) Ethylene glycol
Explanation: Ethylene glycol is commonly used as an antifreeze in automobile radiators due to its ability to lower the freezing point of water.

14. What property of substances is measured by the Mohs scale?

A) Electrical conductivity
B) Thermal conductivity
C) Hardness
D) Viscosity

Correct Answer: C) Hardness
Explanation: The Mohs scale measures the hardness of minerals and other solid substances by comparing their ability to scratch or be scratched by other substances.

15. What does the term 'enthalpy' refer to in thermodynamics?

A) The total kinetic energy of a system
B) The heat content of a system
C) The pressure of a system
D) The volume of a system

Correct Answer: B) The heat content of a system
Explanation: Enthalpy refers to the total heat content of a system, which is used in thermodynamics to calculate the heat absorbed or released during a process at constant pressure.

16. Which gas is used in modern fluorescent lamps to improve their efficiency?

A) Neon
B) Argon
C) Krypton
D) Xenon

Correct Answer: C) Krypton
Explanation: Krypton gas is used in modern fluorescent lamps to improve efficiency and light output, as it helps reduce the power consumption and prolongs the lamp’s lifespan.

17. Which element is primarily responsible for the protective ozone layer in the Earth's stratosphere?

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

Correct Answer: A) Oxygen
Explanation: Oxygen is responsible for the formation of the ozone layer in the Earth’s stratosphere. Ozone (O₃) is formed from oxygen (O₂) under the influence of ultraviolet radiation, providing a protective layer that absorbs most of the sun’s harmful ultraviolet light.

18. Which chemical property determines the number of bonds that an atom can form?

A) Atomic radius
B) Electron affinity
C) Valence
D) Ionization energy

Correct Answer: C) Valence
Explanation: The valence of an atom determines the number of bonds it can form. It refers to the number of electrons an atom uses to bond with other atoms, which is based on its position in the periodic table and its electron configuration.

19. Which element is added to glass to make it resistant to thermal shock?

A) Boron
B) Sodium
C) Silicon
D) Phosphorus

Correct Answer: A) Boron
Explanation: Boron is added to glass to make it resistant to thermal shock. Borosilicate glass, which contains boron, does not crack under extreme temperature changes.

20. Which vitamin is known for being water-soluble and is essential in the synthesis of collagen?

A) Vitamin A
B) Vitamin C
C) Vitamin D
D) Vitamin E

Correct Answer: B) Vitamin C
Explanation: Vitamin C is a water-soluble vitamin essential for the synthesis of collagen, which is vital for the maintenance of skin, blood vessels, bones, and cartilage.

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.