thermodynamics

Question 1

define enthalpy change of formation

Answer 1

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

Question 2

define enthalpy change of atomisation of an element

Answer 2

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

Question 3

define first ionisation energy

Answer 3

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

Question 4

define first electron affinity

Answer 4

the enthalpy change when 1 mole of gaseous 1- ions is formed from 1 mole of gaseous atoms.

Question 5

define enthalpy change of hydration

Answer 5

the enthalpy change when 1 mole of aqueous ions is formed from 1 mole of gaseous ions.

Question 6

define bond dissociation enthalpy

Answer 6

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

Question 7

define enthalpy change of atomisation of a compound

Answer 7

the enthalpy change when 1 mole of a compound in its standard states is converted to gaseous atoms.

Question 8

define second ionisation energy

Answer 8

the enthalpy change when 1 mole of gaseous 2+ ions is formed from 1 mole of gaseous 1+ ions.

Question 9

define second electron affinity

Answer 9

the enthalpy change when 1 mole of gaseous 2- ions is formed from 1 mole of gaseous 1- ions.

Question 10

define enthalpy change of a solution

Answer 10

the enthalpy change when 1 mole of solute is dissolved in enough solvent that no further enthalpy change occurs on further dilution.

Question 11

define lattice enthalpy of formation

Answer 11

the enthalpy change when 1 mole of a solid ionic compound is formed from its gaseous ions under standard conditions.

Question 12

define lattice enthalpy of dissociation

Answer 12

the enthalpy change when 1 mole of a solid ionic compound is completely dissociated into its gaseous ions under standard conditions.