Understanding Exothermic and Endothermic Reactions

What happens to the energy of the products in an exothermic reaction?

• The products have more energy than the reactants.

• The products have less energy than the reactants.

• The products' energy is unrelated to the reactants.

• The products have the same energy as the reactants.

Why do exothermic reactions feel hot to us?

• Because the surroundings release energy.

• Because the system releases energy.

• Because the surroundings absorb energy.

• Because the system absorbs energy.

How is refrigeration considered an exothermic process?

• The refrigerator absorbs heat from the surroundings.

• Heat is released from the food to the surroundings.

• The refrigerator releases heat into the food.

• Heat is absorbed by the food.

In an endothermic reaction, what happens to the energy of the products compared to the reactants?

• The products have less energy than the reactants.

• The products have more energy than the reactants.

• The products' energy is unrelated to the reactants.

• The products have the same energy as the reactants.

Why do endothermic reactions feel cold to us?

• Because the system releases energy.

• Because the surroundings absorb energy.

• Because the surroundings release energy.

• Because the system absorbs energy.

What is an example of an endothermic process?

• Freezing water

• Condensation of water

• Melting ice

• Burning wood

What is activation energy?

• The energy released during a reaction.

• The energy absorbed during a reaction.

• The energy that remains constant during a reaction.

• The energy required to start a reaction.

How do catalysts affect activation energy?

• They decrease the activation energy.

• They increase the activation energy.

• They have no effect on activation energy.

• They eliminate the need for activation energy.

In a graph of an exothermic reaction, what does the area under the curve represent?

• The total energy of the system.

• The energy absorbed by the system.

• The energy released to the surroundings.

• The activation energy.

In a graph of an endothermic reaction, what does the height of the curve represent?

• The total energy of the system.

• The energy absorbed by the system.

• The energy released to the surroundings.

• The activation energy.