Chemistry

Chemical Reactions and Processes

571 Questions

Chemical reactions and processes questions cover the transformation of substances through electrolysis, thermal decomposition, and catalysis. Key areas include identifying gas evolution, balancing chemical equations, and understanding industrial chemical applications. This general chemistry topic is a staple in the science sections of multiple competitive examinations.

Thermal decompositionElectrolysis processGas evolution reactionsHeterogeneous catalystsFuel cell components

Chemical Reactions and Processes Questions

Multiple choice

The overall reaction for steam reforming of methane is:

  1. CH₄ + H₂O → CO + 3H₂

  2. CH₄ + 2H₂O → CO₂ + 4H₂

  3. CH₄ + 3H₂O → CO₂ + 5H₂

  4. CH₄ + 4H₂O → CO₂ + 6H₂
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The overall reaction for steam reforming of methane is CH₄ + 2H₂O → CO₂ + 4H₂.

Multiple choice

What are the main components of a fuel cell?

  1. Anode, cathode, electrolyte, and catalyst

  2. Anode, cathode, salt bridge, and catalyst

  3. Anode, cathode, proton exchange membrane, and catalyst

  4. Anode, cathode, electron transfer mediator, and catalyst
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The main components of a fuel cell include an anode, cathode, electrolyte, and catalyst, which work together to facilitate the electrochemical reactions and generate electricity.

Multiple choice

Which of the following is an example of a chemical kinetic process commonly observed in gas-phase astrochemistry?

  1. Radiative Association

  2. Three-Body Recombination

  3. Dissociative Recombination

  4. Charge Transfer
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Three-Body Recombination is an example of a chemical kinetic process commonly observed in gas-phase astrochemistry, where three particles (typically two atoms and a third body) collide to form a stable molecule.

Multiple choice

What is the term used to describe the chemical reactions that occur in interstellar clouds?

  1. Interstellar chemistry

  2. Cosmic chemistry

  3. Astrochemical reactions

  4. Molecular cloud chemistry
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Interstellar chemistry refers to the chemical reactions that take place within interstellar clouds, leading to the formation of various molecules and compounds.

Multiple choice

What is the chemical reaction that causes popcorn to pop?

  1. The starch inside the kernel turns to steam and expands.

  2. The water inside the kernel turns to steam and expands.

  3. The oil inside the kernel turns to steam and expands.

  4. The protein inside the kernel turns to steam and expands.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When popcorn kernels are heated, the starch inside them turns to steam and expands. This causes the kernel to pop.

Multiple choice

What is the primary chemical reaction that occurs during gasification?

  1. Combustion

  2. Pyrolysis

  3. Hydrogasification

  4. Oxidation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Pyrolysis is the primary chemical reaction that occurs during gasification. It involves the thermal decomposition of the feedstock in the absence of oxygen, resulting in the formation of syngas.

Multiple choice

Which of the following is NOT a type of plasma-chemical reaction?

  1. Dissociation

  2. Ionization

  3. Recombination

  4. Polymerization
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Polymerization is not a plasma-chemical reaction, but rather a chemical reaction that occurs in the presence of a plasma.

Multiple choice

Which of the following is an example of a homogeneous catalyst?

  1. Platinum

  2. Palladium

  3. Hydrochloric acid

  4. Sodium hydroxide
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A homogeneous catalyst is a catalyst that is in the same phase as the reactants. Hydrochloric acid is a homogeneous catalyst because it is a liquid, just like the reactants in many reactions in which it is used.

Multiple choice

Which of the following is an example of a heterogeneous catalyst?

  1. Platinum

  2. Palladium

  3. Hydrochloric acid

  4. Sodium hydroxide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A heterogeneous catalyst is a catalyst that is in a different phase than the reactants. Platinum is a heterogeneous catalyst because it is a solid, while the reactants in many reactions in which it is used are liquids or gases.

Multiple choice

Which of the following is an example of a green chemical reaction?

  1. A reaction that uses a catalytic amount of a metal

  2. A reaction that produces a large amount of waste

  3. A reaction that requires high temperatures and pressures

  4. A reaction that uses toxic chemicals
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Green chemical reactions typically involve the use of catalytic amounts of metals, which reduce the amount of waste produced and minimize the environmental impact.

Multiple choice

How is hydrogen produced?

  1. Electrolysis of water

  2. Steam reforming of natural gas

  3. Gasification of coal

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hydrogen can be produced through a variety of methods, including electrolysis of water, steam reforming of natural gas, and gasification of coal.

Multiple choice

How do fuel cells work?

  1. Hydrogen and oxygen are combined to produce electricity and water

  2. Hydrogen and oxygen are combined to produce heat and water

  3. Hydrogen and oxygen are combined to produce electricity and carbon dioxide

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fuel cells work by combining hydrogen and oxygen to produce electricity and water.

Multiple choice

In etching, the design is created by using a chemical solution to dissolve areas of a metal plate. What is the name of the chemical solution used in this process?

  1. Nitric acid

  2. Hydrochloric acid

  3. Sulfuric acid

  4. Acetic acid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Nitric acid is the most commonly used chemical solution in etching. It is used to dissolve areas of a metal plate, creating the design.

Multiple choice

What is the role of plasma in plasma-enhanced chemical vapor deposition (PECVD)?

  1. To generate reactive species

  2. To create an electric field

  3. To ionize gas molecules

  4. To produce heat
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In PECVD, plasma is used to generate reactive species that participate in chemical reactions, enabling the deposition of thin films with specific properties.

Multiple choice

Which of the following is an example of a chemical process that has been made inherently safer?

  1. The Haber process for producing ammonia.

  2. The Ostwald process for producing nitric acid.

  3. The Solvay process for producing soda ash.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The Haber process, the Ostwald process, and the Solvay process have all been modified over time to make them inherently safer. These modifications have included using less hazardous chemicals, operating at lower temperatures and pressures, and improving containment and control measures.