3.1.8 Thermodynamics Flashcards
(ΔHf)
Enthalpy of formation
The enthalpy change when 1 mole of a compound is formed from its elements
in their standard states.
(ΔHdiss)
Enthalpy of dissosciation
The enthalpy change when all the
bonds of the same type in 1 mole of
gaseous molecules are broken.
(ΔHat)
Enthalpy of atomisation
The enthalpy change when 1 mole of
gaseous atoms is formed from an
element in its standard state.
(ΔHie1)
First ionisation energy
The enthalpy change when 1 mole of
gaseous 1+ ions is formed from 1 mole of gaseous atoms.
(ΔHie2)
2nd ionisation energy
The enthalpy change when 1 mole of
gaseous 2+ ions is formed from 1 mole
of gaseous 1+ ions.
(ΔHea1)
1st electron affinity
The enthalpy change when 1 mole of
gaseous 1- ions is made from 1 mole of
gaseous atoms.
(ΔHea2)
2nd electron affinity
The enthalpy change when 1 mole of
gaseous 2- ions is made from 1 mole of
gaseous 1- ions.
(ΔHhyd)
Enthalpy change of hydration
The enthalpy change when 1 mole of
aqueous ions is formed from gaseous
ions.
(ΔHsolution)
Enthalpy change of solution
The enthalpy change of solution refers to the amount of heat that is released or absorbed during the dissolving process (at constant pressure).
(ΔHlattice) dissosciation
Lattice dissociation enthalpy
The enthalpy change when 1 mole of a
solid ionic compound is completely
dissociated into its gaseous ions.
(ΔHlattice) formation
Lattice formation enthalpy
The enthalpy change when 1 mole of a
solid ionic compound is formed from its
gaseous ions
Is enthalpy of formation ENDO OR EXO
EXO
BOND DISSOSCIATION ENERGY - endo or exo
Endo
Atomization ENDO OR EXO
ENDO
Ionisation energy 1 and 2 endo or exo
ENDO
1st electron affinity ENDO OR EXO (EXPLAIN)
EXOTHERMIC- energy is released when adding an electron to an atom
2nd electron affinity ENDO OR EXO (EXPLAIN)
ENDO it requires energy to add an electron to a negative ion because the negative charges repel
Enthalpy of hydration ENDO OR EXO
EXO
Enthalpy of solution ENDO OR EXO
EITHER
ΔH latt disc endo or exo
endo
ΔH latt form endo or exo
exo
Define entropy
A measurement of disorder in a system
How do you calculate entropy change
ΔS° = ΣS°(products) - ΣS°(reactants)
What are the units of entropy
J K mol-1
What are the units of enthalpy
kJ K mol-1
How do you calculate Gibbs free energy
ΔG° = ΔH° - TΔS°
What does it mean if a reaction is feasible
It will happen
What does it mean if a reaction is spontaneous
A reaction will happen without ‘prompt’ (excluding Ea barrier)
What does the value of G have to be for a reaction to be feasible
0 or below
What are the units of Gibbs free energy
kJ mol-1
