enthalpy defs Flashcards
lattice energy
enthalpy change when 1 mol of solid ionic cmpd is separated into its gaseous ions under s.c.
1st I.E.
energy required to remove 1 mole of electrons from 1 mole of gaseous atoms to form 1 mol of singly charged gaseous atoms
2nd I.E.
energy required to remove 1 mole of electrons from 1 mole of singly charged gaseous atoms to form 1 mol of doubly charged gaseous atoms
1st electron affinity
energy change when 1 mole of electrons is added to 1 mol of gaseous atoms to form 1 mol of singly charged gaseous anions
1st electron affinity
energy change when 1 mole of electrons is added to 1 mol of singly charged gaseous anions to form 1 mol of doubly charged gaseous anions
∆Hhyd
energy released when one mole of gaseous ion is hydrated under s.c.
∆Hhyd depends on…
charge density, |q/r|
greater ∆Hhyd would be bc of
greater CD
∆Hsol
energy change when one mole of substance is completely dissolved in a solvent to form an infintely dilute solution under s.c.
eq for ∆Hsol
LE + ∆Hhyd
combustion
energy released when 1 mole of a substance is completely burnt in excess O2 under s.c.
neutralisation
energy released when 1 mole of water is formed in neutralisation rxn btw acid and base under s.c.
bond energy
average energy required to break 1 mol of covalent bond into gaseous state under s.c.
atomisation
energy absorbed when gaseous atoms are formed from one mole of compound in its standard state under s.c.
