Lattice Enthalpy
Definition enthalpy change when one mole of an
ionic compound is converted into gaseous
ions
Factors
1 ionic radius of ion
size
2 Charge density charge of ion
Values are always positive as
endo ran energy is takenin to breakstrong electrostatic
attractions
offorcesbetween ions
Trends
decreases ionic radius charge remains
same lower chargedensity
F Ci Bi less attractionbetween ions
Nat 918 780 742
ionic radius of G2 ions
K 817 711 679 fromG1 G2 chargefrom G1 G2
t
2526 chargedensity
Mg greaterattractionbetween ion
Ca 2259
i P ionic radius down group
foggy charge remains same
lower chargedensity
less attraction betweenions
, Born Haber Cycles
Enthalpy Formation enthalpychangewhen one moleof a
of compound is formedfromitselements
in theirstandard states
Na leg Nacl
eg s s
Enthalpyof Atomisation enthalpychange when one moleof gaseous
sublimation atoms isformedfrom an element in its
standard state
Na Nacg 1242cg
eg s Cligs
Bond Dissociation Enthalpy enthalpychange when all thebondsof
thesametype in 1 mole ofgaseous
need molecules are broken
2
only if
atoms you You
eg Cycg 24cg
hadot.IEThem
First Ionisation Energy Energyrequired toremove one electronfrom
onemole atoms to produce one mole
ofHgaseous
ions
ofgaseous
Na g Nat e
eg
Second Ionisation
Energy Energyrequired toremove one electronfrom
It ions to produce one more
gorgasian 29 p
eg Na Nat e
Definition enthalpy change when one mole of an
ionic compound is converted into gaseous
ions
Factors
1 ionic radius of ion
size
2 Charge density charge of ion
Values are always positive as
endo ran energy is takenin to breakstrong electrostatic
attractions
offorcesbetween ions
Trends
decreases ionic radius charge remains
same lower chargedensity
F Ci Bi less attractionbetween ions
Nat 918 780 742
ionic radius of G2 ions
K 817 711 679 fromG1 G2 chargefrom G1 G2
t
2526 chargedensity
Mg greaterattractionbetween ion
Ca 2259
i P ionic radius down group
foggy charge remains same
lower chargedensity
less attraction betweenions
, Born Haber Cycles
Enthalpy Formation enthalpychangewhen one moleof a
of compound is formedfromitselements
in theirstandard states
Na leg Nacl
eg s s
Enthalpyof Atomisation enthalpychange when one moleof gaseous
sublimation atoms isformedfrom an element in its
standard state
Na Nacg 1242cg
eg s Cligs
Bond Dissociation Enthalpy enthalpychange when all thebondsof
thesametype in 1 mole ofgaseous
need molecules are broken
2
only if
atoms you You
eg Cycg 24cg
hadot.IEThem
First Ionisation Energy Energyrequired toremove one electronfrom
onemole atoms to produce one mole
ofHgaseous
ions
ofgaseous
Na g Nat e
eg
Second Ionisation
Energy Energyrequired toremove one electronfrom
It ions to produce one more
gorgasian 29 p
eg Na Nat e
