Lattice Enthalpy and entropy

Question 1

entropy (S)

Answer 1

a measure of the dispersal of energy in a system - the greater the entropy, the more disorded a system is

Question 2

enthalpy (H)

Answer 2

a value which represents the heat content of a system

Question 3

free energy change (AG)

Answer 3

AG = AH - TAS (a process is spontaneous/feasible when the AG is negative)

Question 4

enthalpy change of atomisation

Answer 4

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

Question 5

enthalpy change of formation

Answer 5

enthalpy change when one mole of a compound is formed from its elements

Question 6

enthalpy change of hydration

Answer 6

enthalpy change when one mole of gaseous ions is dissolved in water, forming one mole of aqueous ions

Question 7

enthalpy change of solution

Answer 7

enthalpy change when one mole of a compound is completely dissolved in water under standard conditions

Question 8

first electron affinity

Answer 8

the enthalpy change when one mole of gaseous 1- ions is formed from gaseous atoms

Question 9

first ionisation energy

Answer 9

enthalpy change when one mole of gaseous 1+ ions is formed from gaseous atoms

Question 10

lattice enthalpy

Answer 10

enthalpy change when one mole of a solid ionic lattice is formed from its gaseous ions under standard conditions

Question 11

s

second electron affinity

Answer 11

enthalpy change when one mole of gaseous 2- ions is formed from one mole of gaseous 1- ions

Question 12

second ionisation energy

Answer 12

enthalpy change when one mole of gaseous 2+ ions is formed from one mole of gaseous 1+ ions

Question 13

spontaneous reaction

Answer 13

a reaction which can occur at the specified temperature without a constant input of energy