Energetics 2 - enthalpy definitions

Question 1

Lattice enthalpy

Answer 1

The enthalpy change that occurs when 1 mol of an ionic compound is formed from its constituent gaseous ions under standard conditions

Question 2

Enthalpy change of solution

Answer 2

The enthalpy change when 1 mol of a compound dissolves to form a solution of infinite dilution

Question 3

Standard enthalpy change of formation

Answer 3

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

Question 4

First electron affinity

Answer 4

The enthalpy change that occurs when 1 mol of gaseous atoms gains 1 mol of electrons to form 1 mol of gaseous, singly charged negative ions

Question 5

First ionisation energy

Answer 5

The energy required to remove one electron from each atom in 1 mol of gaseous atoms of the element under standard conditions

Question 6

Standard enthalpy change of reaction

Answer 6

The enthalpy change when the molar quantities of reactants as stated in the equation react under standard conditions

Question 7

Enthalpy of atomisation

Answer 7

The enthalpy change when 1 mol of gaseous atoms is formed from the element in its standard state

Question 8

Enthalpy change of hydration

Answer 8

The enthalpy change when 1 mol of gaseous ions dissolve in water to give an infinitely dilute solution

Question 9

Standard enthalpy change of neutralisation

Answer 9

The enthalpy change when the acid and alkali in the equation for the reaction neutralise each other under standard conditions to form 1 mol of water

Question 10

Standard enthalpy change of combustion

Answer 10

The enthalpy change when 1 mol of a compound reacts completely with excess oxygen under standard condition with all reactants and products being in their standard states

Question 11

Bond enthalpy

Answer 11

The enthalpy change when breaking one mole of a given bond in the molecules of a gaseous species