Energetics of Ionic Components Flashcards
define lattice enthalpy
the enthalpy change that accompanies formation of one mole of a solid ionic component in its usual crystal structure from its constituent gaseous ions
define hess’s law
the standard enthalpy of an overall reaction is the sum of the standard enthalpies of the individual reactions into which a reaction may be divided
what are the two ways of calculating lattice enthalpy
born haber cycle
born lande equation
define enthalpy of formation
enthalpy change when one mol of substance is formed from elements in their standard states
define atomisation enthalpy
enthalpy when 1 mol of atoms is formed from elements in their standard states
define bond dissociation enthalpy
enthalpy change when 1 mol of bonds are broken
define ionisation enthalpy
enthalpy for removing one ion from each atom in a mol of substance
define electron affinity
enthalpy change when one mol of substance gains an electron per atom
what is the e in born-lande equation
elementray charge - a contstant of 1.602 x 10^-19
what is backwaards 3 0 symbol in born-lande equation
permittivity of a vacuum - a constant
8.854 x 10 ^-12
what is NA in born-lande equation
avogadros constant - 6.022 x 10^23
what is modulus z+ and z- in born-lande equation
magnitudes of ionic charge
what is r0 in born-lande equation
cation-anion internuclear distance in metres
what is n in born-lande equation
born exponent takes into account repulsion between electron clouds of ions at short distances
how does covalency account for differences in theoretical (born-lande) and experimental (bron-haber) lattice enthalpy
theoretical assumes perfect ionic but they actually have covalent character and distortion
