Unit 2.4 - Chemical Reactions and Energy

Question 1

Explain the difference between exothermic and endothermic reactions in terms of temperature change and energy transfer.

Answer 1

Exothermic reactions give off heat (energy) to the surroundings, while endothermic reactions take in heat (energy) from the surroundings.

Question 2

Define activation energy

Answer 2

The minimum amount of energy needed to start a reaction.

Question 3

Explain the difference between exothermic and endothermic reactions in terms of bonds.

Answer 3

Exothermic: energy given off by making bonds is greater than energy required to break bonds.
Endothermic: energy required to break bonds is greater than energy given off by making bonds.