Chemical Reactions + Energy

Question 1

WHAT IS AN EXOTHERMIC REACTION?

Answer 1

Produces heat

Question 2

WHAT ARE SOME EXAMPLES OF EXOTHERMIC REACTIONS?

Answer 2

• Combustion

• Neutralisation

Question 3

WHAT IS AN ENDOTHERMIC REACTION?

Answer 3

Takes heat in

Question 4

WHAT ARE SOME EXAMPLES OF ENDOTHERMIC REACTIONS?

Answer 4

• Electrolysis

• Thermal decomposition

Question 5

DOES THE PRODUCT OR THE REACTANT HAVE THE HIGHER ENERGY IN AN EXOTHERMIC REACTION?

Answer 5

Reactant

Question 6

DOES THE PRODUCT OR THE REACTANT HAVE THE HIGHER ENERGY IN AN ENDOTHERMIC REACTION?

Answer 6

Product

Question 7

WHAT VALUE DOES THE OVERALL ENERGY CHANGE HAVE IN AN EXOTHERMIC REACTION?

Answer 7

Negative

Question 8

WHAT VALUE DOES THE OVERALL ENERGY CHANGE HAVE IN AN ENDOTHERMIC REACTION?

Answer 8

Positive

Question 9

WHAT ARE THE THREE STEPS FOR BOND CALCULATIONS?

Answer 9

1) Calculate total energy needed to break all bonds in reactants (energy in)

2) Calculate total energy released when product bonds are formed (energy out)

3) Energy change = energy in + energy out

IMPORTANT:
• Energy in = positive
• Energy out = negative