CC15 Energy in Reactions

Question 1

How do catalysts speed up reactions?

Answer 1

They lower activation energy.

Question 2

What is an exothermic reaction?

Answer 2

A reaction where energy is transferred to the surroundings.

Question 3

Give two examples of exothermic reactions.

Answer 3

Combustion, respiration

Question 4

What happens to the temperature of the surroundings during an exothermic reaction?

Answer 4

They increase.

Question 5

What is an endothermic reaction?

Answer 5

A reaction where energy is transferred from the surroundings.

Question 6

What happens to the temperature of the surroundings during an endothermic reaction?

Answer 6

They decrease.

Question 7

What are reactants?

Answer 7

The substances involved in a chemical reaction

Question 8

What are products?

Answer 8

The substances formed when reactants have a chemical reaction

Question 9

Is breaking bonds endothermic or exothermic?

Answer 9

Endothermic. Chemical bonds are strong so require energy to break.

Question 10

Is making bonds endothermic or exothermic?

Answer 10

Exothermic. Energy is released when chemical bonds are formed.

Question 11

If more heat energy is released forming bonds than is required for breaking bonds in a reaction what kind of reaction is it?

Answer 11

exothermic

Question 12

If less heat energy is released forming bonds than is required for breaking bonds in a reaction what kind of reaction is it?

Answer 12

endothermic