Thermodynamics - L5 - contributions to enthalpy

h gen chem 1

the change in enthalpy of ionization

is the change in standard enthalpy per mole of atoms for the loss of an electron

enthalpy of electron gain

the analogous quantity for the gain of an electron

born-haber cycle

a thermochemical model that uses hess’s law to calculate the lattice energy of an ionic compound

lattice enthalpy of a solid

the difference in molar enthalpy between the solid and a gas of widely spread ions

bond enthalpy

the difference between the standard molar enthalpies of a molecule

bond dissociation energy

energy required to break a bond a t=0

bond enthalpies and bond energies can be used

interchangeably

bond enthalpies arent

the most precise, because they can exist in a variety of molecules that could have more specific values

the enthalpies of both reactants and products increase with

temperature

electrostatic attraction is large

when charges are large and close together (high charge, smaller atoms)

smaller atoms=

shorter, stronger bonds

lone pairs

weaken a neighboring bond