Chemistry A Level Definitions

Question 1

What is the definition of first ionisation energy ?

Answer 1

The first ionisation energy is the energy needed to remove 1 electron from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions

Question 2

What is the definition of the second ionisation energy

Answer 2

The second ionisation energy is the energy needed to remove 1 electron from each ion in 1 mole of gaseous 1+ ions to form 1 mole of gaseous 2+ ions

Question 3

Bond Enthalpy

Answer 3

Standard enthalpy change associated with breaking one mole of bonds in a gaseous substance into individual gaseous atoms

Question 4

standard enthalpy change of combustion

Answer 4

the enthalpy change when one mol of a substance reacts completely with oxygen under standard conditions and all chemicals are in there standard states

Question 5

standard enthalpy change of formation

Answer 5

the enthalpy change when one mole of a compound is formed from its elements under standard conditions and all chemicals are in standard states