enthalpy - definitions

Question 1

enthalpy of formation

Answer 1

enthalpy change when 1 mole of a substance is formed from it’s constituent elements under standard conditions in their standard states

Question 2

enthalpy change of combustion

Answer 2

enthalpy change when 1 mole of substance undergoes complete combustion in oxygen with all substances in standard states

Question 3

enthalpy change of neutralization

Answer 3

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

Question 4

ionization enthalpy

Answer 4

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

Question 5

electron affinity

Answer 5

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

Question 6

enthalpy of atomization

Answer 6

enthalpy change when 1 mole of gaseous atoms is produced from an element in standard state

Question 7

hydration energy

Answer 7

enthalpy when 1 mole of gaseous ions become hydrated (dissolved in water)

Question 8

enthalpy of solution

Answer 8

enthalpy change when one mole of an ionic substance is dissolved in a large enough amount of water so that the dissolved ions are well separated and do not interact

Question 9

bond dissociation enthalpy

Answer 9

enthalpy change when one mole of covalent bonds is broken in the gaseous states

Question 10

lattice enthalpy of formation

Answer 10

enthalpy change when I mole of solid ionic compound is formed from it’s constituent elements in the gas phase

Question 11

lattice enthalpy of dissociation

Answer 11

enthalpy change when 1 mole of solid ionic compound is broken up into it’s constituent elements in the gas phase

Question 12

enthalpy of vaporization

Answer 12

enthalpy change when 1 mole of liquid is turned into a gas

Question 13

enthalpy of fusion

Answer 13

enthalpy change when one mole of solid is turned into a liquid