Thermochemistry and Reaction Types

What is thermochemistry?

• The study of heat changes during chemical reactions.

• The study of temperature changes in physical processes.

• The study of energy transfer in biological systems.

• The study of chemical bonds and their formation.

Which statement best describes an endothermic reaction?

• A reaction that releases heat to the surroundings.

• A reaction that absorbs heat from the surroundings.

• A reaction that produces light energy.

• A reaction that forms new chemical bonds.

What happens in an exothermic reaction?

• Heat is absorbed from the surroundings.

• Heat is released to the surroundings.

• The temperature of the system decreases.

• The reactants gain energy.

Which of the following is an example of an endothermic reaction?

• Combustion

• Freezing

• Melting of ice

• Respiration

What happens to the surrounding temperature during an endothermic reaction?

• It increases.

• It decreases.

• It remains constant.

• It fluctuates unpredictably.

Photosynthesis is a process where plants absorb energy from sunlight to convert carbon dioxide and water into oxygen and glucose. What type of reaction is photosynthesis?

• Exothermic

• Combustion

• Endothermic

• Oxidation

Baking a cake involves a chemical reaction where heat is absorbed from the oven to produce carbon dioxide bubbles, making the cake light and fluffy. This is an example of what type of reaction?

• Exothermic

• Endothermic

• Combustion

• Neutralization

Which of these processes is an example of an exothermic reaction?

• Boiling of water

• Melting of ice

• Respiration

• Frying an egg

In an exothermic reaction, how does the total energy content of the product compare to the total energy content of the reactants?

• It is more.

• It is less.

• It is the same.

• It cannot be determined.

Combustion is an oxidation reaction that produces heat, where hydrocarbons react with oxygen to form water and carbon dioxide. What type of reaction is combustion?

• Endothermic

• Photosynthesis

• Decomposition

• Exothermic