Kinetics and thermodynamics Flashcards
How is lattice formation enthalpy calculated from a Born-Haber cycle?
Follow the around back around
If the direction is reversed then take away, if it is in the same direction then add
What is entropy?
A measure of disorder
What factors affect entropy?
State: gases>liquid>solid
No moles: More moles = higher entropy
Complexity: More complex molecule =. higher entropy
ΔS =
ΔS(products) - ΔS(reactants)
What is Gibb’s free energy?
A measure of whether a reaction will be spontaneous or not
ΔG=
ΔG= ΔH-TΔS
If ΔG=0…
T=ΔH/ΔS to find the temperature at which a reaction becomes feasible
ΔH solution is
The enthalpy change when 1 mole of an ionic compound is dissolved in water to produce aqueous ions
ΔH solution =
ΔH lattice breaking - ΔH hydration
What is ΔH lattice breaking?
Enthalpy change from the breaking of a lattice into its constituent gaseous ions
What is ΔH hydration?
Enthalpy change when one moles of gaseous ions is converted into one mole of aqueous ions
What is ΔH atomisation?
Enthalpy change when one mole of gaseous atoms are formed from its constituent elements
What is ΔH electron affinity?
Opposite of ionisation energy
Enthalpy change when one mole of gaseous atoms converts into one mole of gaseous anions, each atom gaining one electron
What dictates a compounds stability?
Whether it is endothermic or exothermic
How stable is a reaction if it is very exothermic?
Unstable, no energy is needed to be added for the reaction to occur
