lattice enthalpy

Question 1

what is ‘lattice enthalpy’?

Answer 1

a measure of the strength of ionic bonding in a giant ionic lattice

Question 2

what is the definition of ‘lattice enthalpy’ in terms of enthalpy change?

Answer 2

the enthalpy change that accompanies the formation of one mole of an ionic compound from its gaseous ions under standard conditions

Question 3

is lattice enthalpy endo or exothermic?

Answer 3

exothermic
- bonds are formed

Question 4

define ‘enthalpy of formation’

Answer 4

enthalpy change when one mole of a compound forms from its elements under standard conditions

Question 5

define ‘first ionisation enthalpy’

Answer 5

enthalpy change when one electron is removed from one mole of gaseous atoms of an element to form one mole of gaseous + ions

Question 6

define ‘second ionisation enthalpy’

Answer 6

enthalpy change when one electron is removed from one mole of gaseous + ions to form one mole of gaseous 2+ ions

Question 7

is ionisation enthalpy exo or endothermic?

Answer 7

endothermic

Question 8

is enthalpy of formation exo or endothermic?

Answer 8

exothermic

Question 9

define ‘first electron affinity’

Answer 9

enthalpy change when one electron is added to each atom in one mole of gaseous atoms to form one mole of gaseous - ions

Question 10

define ‘second electron affinity’

Answer 10

enthalpy change when one electron is added to each ion in one mole of gaseous - ions to form one mole of gaseous 2- ions

Question 11

is first electron affinity exo or endothermic?

Answer 11

exothermic

Question 12

is second electron affinity exo or endothermic?

Answer 12

endothermic

Question 13

define ‘enthalpy of atomisation’

Answer 13

enthalpy change when one mole of gaseous atoms is formed from its element in standard state

Question 14

is atomisation exo or endothermic?

Answer 14

endothermic

Question 15

what do we use a born haber cycle for?

Answer 15

indirectly calculating lattice enthalpy

Question 16

what goes at the bottom of a born haber cycle?

Answer 16

the solid ionic compound

Question 17

what is the first born haber step and which direction is the arrow?

Answer 17

enthalpy of formation
downwards (exothermic)

Question 18

what is the second born haber step and which direction is the arrow?

Answer 18

atomisation
upwards (endothermic)

Question 19

what is the third born haber step and which direction is the arrow?

Answer 19

ionisation
upwards (endothermic)

Question 20

what is the fourth born haber step and which direction is the arrow?

Answer 20

electron affinity
downwards (exothermic)

Question 21

what is the last born haber step and which direction is the arrow?

Answer 21

lattice enthalpy
downwards (exothermic)

Question 22

what happens in a born haber cycle if an anion has a charge greater than one?

Answer 22

use successive electron affinities
(second is upwards)