Thermodynamics

Question 1

what is enthalpy of lattice formation

Answer 1

Standard enthalpy change when 1 mole of an ionic crystal lattice is formed from its constituents ions in gaseous form

Question 2

what is enthalpy of lattice dissociation

Answer 2

Standard enthalpy change when 1 mole of an ionic crystal lattice form is separated into its constituents in gaseous form

Question 3

what is the enthalpy change of formation

Answer 3

Energy transferred when 1 mile of the compound is formed from its elements under standard conditions ( 298k and 100kpa) , all reactants and products being in their standard states

Question 4

what is enthalpy of atomisation

Answer 4

Is the enthalpy change when 1 mole of gaseous atoms is formed from the element in its standard states

Question 5

what is bond dissociation enthalpy

Answer 5

Standard molar enthalpy change when one mole of a covalent bond is broken into two gaseous atoms

Question 6

what is the first ionisation enthalpy

Answer 6

Enthalpy change required to remove 1 mole of electrons from 1 mole of gaseous atoms to form 1 mole of gaseous ions with a +1 charge

Question 7

second ionisation enthalpy

Answer 7

the enthalpy change to remove 1 mole of electrons from one mole of gaseous +1 ions to produce one mole of gaseous 2+ ions

Question 8

what is the first electron affinity

Answer 8

Enthalpy change that occurs when 1 mole of gaseous atoms gain 1 mole of electrons to form 1 mole of gaseous ions with a -1 charge

Question 9

what is the second electron affinity

Answer 9

the enthalpy change when one mole of gaseous 1- ions gains one electron per ion to produce gaseous 1- ions

Question 10

what is enthalpy change

Answer 10

heat energy at constant pressure

Question 11

EQ : In terms of the forces acting on particles , suggest one reason why the first electron affinity of oxygen is an exothermic process (1)

Answer 11

There’s an attractive force between the nucleus of an O atom and an external electron