thermodynamic definitions

Question 1

enthalpy of atomisation (solid to gas)

Answer 1

the enthalpy change when 1 mole of gaseous atoms is formed from the element in its standard state

Question 2

bond dissociation enthalpy (Cl2 (g)&raquo_space;> 2Cl (g)

Answer 2

Enthalpy change when 1 mole of covalent bonds is broken into 2 gaseous atoms

Question 3

first electron affinity (O (g) + e- >. O- (g) )

Answer 3

the enthalpy change when 1 mole of gaseous atoms gain 1 mole of electrons to form 1 mole of gaseous 1- ions

Question 4

Enthalpy lattice of formation (Na+ (g) + Cl- (g)&raquo_space;> NaCl (s))

Answer 4

Enthalpy change when 1 mole of solid ionic compound is formed from its constituent ions in the gas phase.

Question 5

Enthalpy lattice of dissociation (NaCl (s)&raquo_space; Na+ (g) + Cl- (g) )

Answer 5

Enthalpy change when 1 mole of solid ionic compound is broken up into its constituent ions in the gas phase.

Question 6

enthalpy of hydration (X+(g) + aq+&raquo_space;> X+(aq) )

Answer 6

Enthalpy change when one mole of gaseous ions become aqueous ions . (attraction between metal ion and Oδ- of water)

Question 7

enthalpy of solution (NaCl (s)&raquo_space;> Na+ (aq) + Cl-(aq)

Answer 7

enthalpy change when one mole of a solid ionic compound dissolves in a amount of water large enough to ensure that the dissolved ions are well separated and don’t interact with one another