definitions

Question 1

enthalpy change of formation

Answer 1

enthalpy change when one mole of a substance is made from its elements in there standard states

Question 2

enthalpy change of combustion

Answer 2

enthalpy change when one mole of a substance undergoes complete combustion in oxygen with all substances in standard states

Question 3

enthalpy change of neutralisation

Answer 3

enthalpy change when 1 mole of water is formed in a reaction between an acid and alkali under standard conditions

Question 4

first ionisation energy

Answer 4

enthalpy change when each atom in one mole of
gaseous atoms loses one electron to form one mole of gaseous 1+ ions

Question 5

second ionisation energy

Answer 5

enthalpy change when each ion in one mole of gaseous 1+ ions loses one electron to form one mole of gaseous 2+ ions

Question 6

first electron affinity

Answer 6

enthalpy change when each atom in one mole of
gaseous atoms gains one electron to form one mole of gaseous 1– ions

Question 7

second electron affinity

Answer 7

enthalpy change when each ion in one mole of gaseous 1– ions gains one electron to form one mole of gaseous 2– ions

Question 8

enthalpy change of atomisation

Answer 8

enthalpy change when one mole of gaseous atoms is produced from an element in its standard state

Question 9

hydration enthalpy

Answer 9

enthalpy change when one mole of gaseous ions dissolves in water

Question 10

enthalpy of solution

Answer 10

enthalpy change when one mole of an ionic solid dissolves in water

Question 11

lattice enthalpy

Answer 11

enthalpy change when one mole of a solid ionic compound is formed from its constituent ions in the gas phase