inorganic solids Flashcards
(30 cards)
what is the lattice enthalpy
the change in enthalpy when one mole of an ionic solid is converted into gaseous ions
what are the methods for determining the lattice enthalpies
- using experimentally derived thermodynamic data in born haber cycles.
- using calculations
what is hess’s law
states that the reaction enthalpy is always the same regardless of whether the reaction takes place in one step or many.
why is the Kapustinskii equation better than the madelung constant
you don’t need a detailed knowledge the crystal structure
what unit must r be in for the kapustinskii equation
pm
packing efficiency =
area occupied by circles / area of unit cell
what is the area of a parallelogram
absin60
what does sin60 =
root3/2
coordination number of an atom is
the number of other atoms its touching
stacking sequence for hexagonal close packed
ABA
stacking sequence for cubic close packed
ABCA
what is the number of atoms in a primitive unit cell
1
what is the number of atoms in a body centred cubic unit cell
2
what is the number of atoms in a face centred cubic unit cell
4
what is the number of atoms in a hexagon unit cell
2
what is the coordination number of atoms in a primitive unit cell
6
what is the coordination number of atoms in a body centred cubic unit cell
8
what is the coordination number of atoms in a face centred cubic unit cell
12
what is the coordination number of atoms in a hexagonal unit cell
12
what is the relationship between a and r in a primitive unit cell
a=2r
what is the relationship between a and r in a body centred cubic unit cell
a = 4r/root3
what is the relationship between a and r in a face centred cubic unit cell
a = 4r/root2
density (p) =
mass/volume (m/v)
1A = — cm
x10^-8
