DF - Hess's law

Question 1

bond enthalpy

Answer 1

average value of the energy is takes for one mole of a bond to break under standard conditions

Question 2

enthalpy change of formation

Answer 2

one mole of a substance produced from its elements

Question 3

enthalpy change of combustion

Answer 3

one mole of a substance to completely burn in oxygen

Question 4

enthalpy change of neutralisation

Answer 4

solutions of acid and alkali react to produce one mole of water