Chemical Reactions

What is an exothermic reaction?

• An exothermic reaction has no change in energy

• An exothermic reaction only releases energy in the form of sound

• An exothermic reaction releases energy in the form of heat or light.

• An exothermic reaction absorbs energy from the surroundings

Give an example of an exothermic reaction.

• Freezing of water

• Combustion of methane

• Photosynthesis

• Boiling of ethanol

What is an endothermic reaction?

• A reaction that releases heat to its surroundings.

• A reaction that involves a change in color.

• A reaction that occurs at a constant temperature.

• A reaction that absorbs heat from its surroundings.

Provide an example of an endothermic reaction.

• Ammonium nitrate + Water -> Ammonium nitrate solution (endothermic)

• Hydrochloric acid + Sodium hydroxide -> Sodium chloride + Water (exothermic)

• Iron + Oxygen -> Iron oxide (exothermic)

• Methane + Oxygen -> Carbon dioxide + Water (exothermic)

How can you tell if a reaction is exothermic?

• Listen for a loud noise

• Smell a strong odor

• Feel the container getting warmer

• Check the color of the reactants

How can you tell if a reaction is endothermic?

• The reaction produces a gas.

• Observe a decrease in temperature during the reaction.

• The reaction occurs rapidly.

• Observe an increase in temperature during the reaction.

What happens to the energy in an exothermic reaction?

• It is released to the surroundings.

• It is converted into matter.

• It disappears without a trace.

• It is absorbed by the reactants.

What happens to the energy in an endothermic reaction?

• Energy is absorbed

• Energy remains constant

• Energy is released

• Energy is converted to matter

Which type of reaction absorbs heat from the surroundings?

• Endothermic

• Thermogenic

• Exothermic

• Endogenic

Which type of reaction releases heat into the surroundings?

• Exergonic reaction

• Exothermic reaction

• Endothermic reaction

• Thermodynamic reaction