12. Thermodynamics

Question 1

Standard Molar Enthalpy of Formation

Answer 1

The enthalpy change when one mole of a compound is formed from its constituent elements under standard conditions, all reactants and products in their standard states

Question 2

Standard Enthalpy of Atomisation

Answer 2

The enthalpy change on the formation of one mole of gaseous atoms from the element in its standard state under standard conditions

Question 3

First Ionisation Energy

Answer 3

The standard enthalpy change when one electron is removed from every atom in one mole of gaseous atoms to produce one mole of gaseous monopositive ions

Question 4

Second Ionisation Energy

Answer 4

The standard enthalpy change when one electron is removed from every ion in one mole of gaseous monopositive ions to produce one mole of gaseous dispositive ions

Question 5

First Electron Affinity

Answer 5

The standard enthalpy change when one electron is added to every atom in one mole of gaseous atoms to produce one mole of gaseous mononegative ions

Question 6

Second Electron Affinity

Answer 6

The standard enthalpy change when one electron is added to every ion in one mole of gaseous mononegative ions to produce one mole of gaseous dinegative ions

Question 7

Lattice Enthalpy of Formation

Answer 7

The standard enthalpy change when one mole of an ionic crystal lattice is made from its constituent ions in their gaseous states

Question 8

Lattice Enthalpy of Dissociation

Answer 8

The standard enthalpy change when one mole of an ionic crystal lattice is broken down into its consistent ions in their gaseous states

Question 9

Enthalpy of Hydration

Answer 9

The standard enthalpy change when water molecules surround one mole of gaseous ions

Question 10

Enthalpy of Solution

Answer 10

The standard enthalpy change when one mole of an ionic substance dissolves in a large enough amount of solvent to ensure that the aqueous ions are far enough apart to ensure they do not react with one another

Question 11

Bond Enthalpy

Answer 11

The standard enthalpy change on breaking one mole of a covalent bond in a gaseous molecule to produce two gaseous free radicals

Question 12

Mean Bond Enthalpy

Answer 12

The standard enthalpy change on breaking one mole of a covalent bond in a gaseous molecule to produce two gaseous free radicals, averaged over a range of compounds