5.3 enthalpy, entropy and free energy

Question 1

mean bond enthalpy

Answer 1

average enthalpy change when one mole of a given bond is broken in a range of molecules

Question 2

standard enthalpy of formation

Answer 2

enthalpy change when one mole of a substance is formed from elements under standard conditions

Question 3

standard enthalpy of combustion

Answer 3

enthalpy change when one mole of a substance is completely burnt in oxygen

Question 4

standard enthalpy of atomisation

Answer 4

enthalpy change when one mole of gaseous atoms form from elements in the standard state

Question 5

enthalpy change of hydration

Answer 5

enthalpy change when one mole of gaseous ions from aqueous ions

Question 6

standard enthalpy change of solution

Answer 6

enthalpy change when one mole of solute forms a solution

Question 7

first ionisation energy

Answer 7

the energy required to remove one electron from each of one mole of gaseous atoms to an infinite separation.

Question 8

first electron affinity

Answer 8

enthalpy change when one mole of a gaseous atoms form one mole of gaseous ions with a negative charge

Question 9

lattice enthalpy of formation

Answer 9

enthalpy change when one mole of a solid ionic compound is formed from gaseous ions

Question 10

lattice enthalpy of dissociation

Answer 10

enthalpy change when one mole of a solid ionic compound is dissociated into gaseous ions

Question 11

what is entropy

Answer 11

how disordered a reaction is

Question 12

positive gibbs free energy value:

Answer 12

not feasible at that temp

Question 13

negative gibbs free energy value:

Answer 13

not feasible at that temp