Introduction to Reaction Profiles: Exothermic and Endothermic Reactions and Activation Energy

The video tutorial covers exothermic and endothermic reactions, explaining how energy is transferred in each type. Exothermic reactions release energy to the surroundings, resulting in a negative delta H, while endothermic reactions absorb energy, leading to a positive delta H. The concept of activation energy is also discussed, highlighting the minimum energy required for reactions to occur. Energy level diagrams are used to illustrate these concepts, showing the energy changes between reactants and products.

What is a key characteristic of exothermic reactions?

• They release energy to the surroundings.

• They absorb energy from the surroundings.

• They have a positive delta H.

• They do not involve energy changes.

In an exothermic reaction, how do the energy levels of products compare to reactants?

• Energy levels are not relevant in exothermic reactions.

• Products have lower energy levels than reactants.

• Products have the same energy levels as reactants.

• Products have higher energy levels than reactants.

Which of the following is true for endothermic reactions?

• They do not involve energy changes.

• They have a negative delta H.

• They absorb energy from the surroundings.

• They release energy to the surroundings.

What happens to the surroundings during an endothermic reaction?

• They heat up.

• They cool down.

• They remain unchanged.

• They become more reactive.

What is activation energy?

• The minimum energy needed for a reaction to occur.

• The energy released during a reaction.

• The energy difference between reactants and products.

• The energy required to form products.