Understanding Exothermic and Endothermic

What is the definition of an exothermic reaction?

• An exothermic reaction occurs only in gases.

• An exothermic reaction is a process that does not involve heat transfer.

• An exothermic reaction is a reaction that releases energy, usually in the form of heat.

• An exothermic reaction absorbs energy from the surroundings.

What is the definition of an endothermic reaction?

• An endothermic reaction occurs spontaneously without energy input.

• An endothermic reaction is a reaction that absorbs heat.

• An endothermic reaction releases heat.

• An endothermic reaction is a process that generates heat.

Can you provide an example of an exothermic reaction?

• Combustion of methane (CH4 + 2O2 -> CO2 + 2H2O) is an example of an exothermic reaction.

• Dissolving ammonium nitrate in water is an exothermic reaction.

• Photosynthesis (6CO2 + 6H2O -> C6H12O6 + 6O2) is an example of an exothermic reaction.

• Rusting of iron (4Fe + 3O2 -> 2Fe2O3) is an example of an exothermic reaction.

Can you provide an example of an endothermic reaction?

• Combustion

• Respiration

• Dissolution of salt in water

• Photosynthesis

What happens to energy during an exothermic reaction?

• Energy is absorbed from the surroundings.

• Energy is released into the surroundings.

• Energy remains constant throughout the reaction.

• Energy is converted into mass.

What happens to energy during an endothermic reaction?

• Energy remains constant throughout the reaction.

• Energy is converted into mass during the reaction.

• Energy is released into the surroundings.

• Energy is absorbed from the surroundings.

How can you identify if a reaction is exothermic or endothermic?

• Exothermic reactions always occur at low temperatures, while endothermic reactions occur at high temperatures.

• A reaction is exothermic if it absorbs heat and endothermic if it releases heat.

• A reaction is endothermic if it produces light and exothermic if it produces sound.

• A reaction is exothermic if it releases heat and endothermic if it absorbs heat.

What role do energy changes play in chemical reactions?

• Energy changes are irrelevant to the speed of reactions.

• Energy changes only affect physical processes, not chemical ones.

• Energy changes have no impact on chemical reactions.

• Energy changes dictate the nature and feasibility of chemical reactions.