Energetics

Question 1

What is an exothermic reaction?

Answer 1

a reaction that:
- transfers thermal energy to the surroundings
- leading to an increase in the temperature of the surroundings

Question 2

What is an endothermic reaction?

Answer 2

a reaction that:
- takes in thermal energy from the surroundings
- leading to a decrease in the temperature of the surroundings

Question 3

What is enthalpy change?

Answer 3

the transfer of thermal energy during a reaction

Question 4

What is the enthalpy change in an ENDOTHERMIC reaction?

Answer 4

positive - takes in thermal energy from surroundings

Question 5

What is the enthalpy change in an EXOTHERMIC reaction?

Answer 5

negative - loses energy to surroundings

Question 6

What is activation energy?

Answer 6

the minimum energy that colliding particles must have to react

Question 7

In endothermic reactions, are bonds made or broken?

Answer 7

bonds are broken

Question 8

In exothermic reactions, are bonds made or broken?

Answer 8

bonds are made

Question 9

Does bond breaking release or take in energy?

Answer 9

takes in (needs energy to break bonds)

Question 10

Reaction taking in energy:

Answer 10

endothermic

Question 11

Reaction giving out energy:

Answer 11

exothermic

Question 12

Endothermic reactions ______ heat.

Answer 12

absorb

Question 13

Exothermic reactions ______ heat.

Answer 13

release