Topic 8 - Energetics 1

Question 1

What is negative enthalpy change?

Answer 1

Heat given out - exothermic

Question 2

What is positive enthalpy change?

Answer 2

Takes in heat - endothermic

Question 3

What are standard conditions?

Answer 3

Pressure 1 bar
298K

Question 4

What’s the definition of the standard enthalpy of combustion?

Answer 4

The enthalpy change of combustion is the enthalpy change when one mole of a substance in its standard state burns completely in oxygen under standard conditions.

Question 5

What’s the definition of the enthalpy change of formation?

Answer 5

The enthalpy change of formation is the enthalpy change when one mole of a substance is formed in it’s standard state from pure elements in their standard states under standard conditions.

Question 6

What is the definition of the enthalpy change of neutralisation?

Answer 6

The enthalpy change of neutralisation is the enthalpy change that accompanies the formation of one mole of H2O when an acid and a base react, in their standard states, under standard conditions.