3.2.1 Enthalpy Changes

Question 1

What energy change is breaking bonds associated with?

Answer 1

Energy is taken in to break bonds
———> Endothermic

Question 2

What energy change is making bonds associated with?

Answer 2

Energy is released to make bonds
Exothermic

Question 3

What overall enthalpy change does an endothermic reaction have?

Answer 3

Overall positive

Question 4

What overall enthalpy change does an exothermic reaction have?

Answer 4

Overall negative

Question 5

What does activation energy mean?

Answer 5

The minimum amount of energy required for a reaction to take place

Question 6

What are standard conditions?

Answer 6

100kPa
298 Kelvin

Question 7

Define the enthalpy change of formation

Answer 7

The energy change from when 1 mol of a substance is formed from its constituent elements

Question 8

Define enthalpy change of combustion

Answer 8

The energy change when one mol of a substance is completely combusted

Question 9

Define enthalpy change of neutralisation

Answer 9

The energy change when 1 mol of water is produced from an neutralisation reaction

Question 10

What does enthalpy change of reaction mean?

Answer 10

The energy change associated with a given reaction