enthalpy and entropy

Question 1

lattice enthalpy

Answer 1

the enthalpy change which accompanies the formation of one mole of ionic compound from its gaseous ions under standard conditions

Question 2

enthalpy change of formation

Answer 2

the enthalpy change that takes place when one mole of a compound is formed from its elements under standard conditions with all its reactants and products in their standard states

Question 3

enthalpy change of atomisation

Answer 3

the enthalpy change that takes place for the formation of one mole of gaseous atoms from the elements in its standard state under standard conditions

Question 4

first ionisation energy

Answer 4

the enthalpy change required to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions

Question 5

first electron affinity

Answer 5

the enthalpy change that takes place when one electron is added to each atom in one mole of gaseous atoms to form one mole of gaseous 1- ions

Question 6

why are second electron affinities endothermic?

Answer 6

a second electron is being gained by a negative ion, which repels the electron away. so energy must be put into force the negatively-charged electron onto the negative ion

Question 7

enthalpy change of hydration

Answer 7

the enthalpy change which accompanies the formation of 1 mole of aqueous ions from 1 mole of its gaseous ions under standard conditons

Question 8

enthalpy change of solution

Answer 8

the enthalpy change that takes place when one mole of solute dissolves in a solvent