12B.2

Question 1

what is experimental lattice energy

Answer 1

it is a lattice energy calculated from the born-haber cycle

Question 2

the type of lattice structure and the inter ion distance can be found by

Answer 2

X-ray crystallography

Question 3

to calculate the lattice energy what assumptions do we make

Answer 3

1. the ions are in contact with each other
2. the ions are perfectly spherical
   3, the charge of the ions is evenly distributed in the centre making the ions be considered as a point of charge

Question 4

what is theoretical lattice energy

Answer 4

lattice energy that is calculated using the principles of electrostatics

Question 5

why are the theoretical values of lattice energy sometimes less that the experimental lattice energies

Answer 5

because in theoretical lattice energy the covalent character caused by the polarization of the anion is not included

Question 6

what is polarization

Answer 6

the distortion of electron density of an anion

Question 7

why does polarization form a covalent character

Answer 7

because the polarization of the anion causes the distribution of the electron density of the anion which would result in a higher electron density in the cation so there will be some electron density between the two ions = covalent character

Question 8

polarization will increase by

Answer 8

1. small cation + high charge
2. big anion + high charge

Question 9

what is polarization power

Answer 9

the ability of a cation to attract the anion electrons to its self

Question 10

more polarization is a result of

Answer 10

more polarization power of the cation

Question 11

charge density

Answer 11

charge / r^2

Question 12

greater covalent character (bond) is a result of

Answer 12

greater polarization

Question 13

what ions are easiest to polarize

Answer 13

high charge + large size