energetics definitions on enthalpy change

Question 1

enthalpy change of reaction

Answer 1

enthalpy change when quantities of substances in standard states react completely under standard conditions

Question 2

enthalpy change of formation

Answer 2

enthalpy change when one mole of a substance is produced from its elements under standard condition

Question 3

enthalpy change of combustion

Answer 3

enthalpy change when one mole of a substance is burned completely in oxygen under standard conditions

Question 4

enthalpy change of neutralisation

Answer 4

enthalpy change when solutions of acid and alkali react together under standard conditions to produce one mole of water

Question 5

bond enthalpy

Answer 5

average value of the bond energy required to break 1 mole of a bond

Question 6

mean bond enthalpy formula

Answer 6

enthalpy change of bonds breaking-enthalpy change of bonds forming

Question 7

lattice dissociation enthalpy definition

Answer 7

enthalpy change when one mole of a solid ionic compound is completely dissociated into its gaseous constituent ions under standard conditions

-endothermic
-ionic substances

Question 8

lattice formation enthalpy

Answer 8

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

-exothermic

Question 9

atomisation enthalpy definition

Answer 9

energy required for the formation of 1 mole of gaseous atoms from an element under standard conditions

Question 10

enthalpy of electron affinity

Answer 10

enthalpy change when 1 mole of electron is added to 1 mole of gaseous atoms to form 1 mole of gaseous -1 ions under standard conditions