Enthalpy

Question 1

Enthalpy change

Answer 1

Enthalpy change is the heat energy transferred in a reaction at a constant pressure.

Question 2

Lattice formation enthalpy

Answer 2

The enthalpy change when 1 mole of a solid ionic compound is formed from its gaseous ions.

Question 3

Lattice dissociation enthalpy

Answer 3

The enthalpy change when 1 mole of solid ionic compound is completely dissociated into its gaseous ions.

Question 4

Enthalpy change of formation

Answer 4

The enthalpy change when 1 mole of a compound is formed from its elements in their standard states under standard conditions

Question 5

Bond dissociation enthalpy

Answer 5

The enthalpy change when all the bonds of the same type in 1 mole of gaseous molecules are broken.

Question 6

Atomisation of an element

Answer 6

The enthalpy change when 1 mole of gaseous atoms is formed from an element in its standard state.

Question 7

Atomisation of a compound

Answer 7

The enthalpy change when 1 mole of a compound in its standard state is converted into gaseous atoms.

Question 8

First ionisation energy

Answer 8

The enthalpy change when 1 mole of gaseous 1+ ions is formed from 1 mole of gaseous atoms.

Question 9

First electron affinity

Answer 9

The enthalpy change when 1 mole of gaseous 1- ions is made from 1 mole of gaseous atoms.

Question 10

Enthalpy of hydration

Answer 10

The enthalpy change when 1 mole of aq ions is formed from gaseous ions.

Question 11

Enthalpy of solution

Answer 11

The enthalpy change when 1 mole of ionic substance dissolves in enough solvent to form an infinitely dilute solution (contains so much solvent that when you add liquid there is no change in concentration).

Question 12

enthalpy change of combustion

Answer 12

the enthalpy change when 1 mole of substance is burned in oxygen under standards conditions with all reactants and products in their standard states