5.2.1 Notes And Definitions

Question 1

Define lattice Enthalpy

Answer 1

Enthalpy change that accompanies the formation of one mole of an ionic compound from its gaseous ions under standard conditions

(g) —> (s)

Question 2

Define standard Enthalpy change of solution

Answer 2

Takes place when 1 mole of a solute dissolves in a solvent

s) —> (aq

Question 3

Define standard Enthalpy change of hydration

Answer 3

Dissolving of gaseous ions in water to form one mole of aqueous ions

(g) —> (aq)

Question 4

What is the effect on ion size in lattice Enthalpy?

Answer 4

Ionic radius increases, attraction between ions decreases, lattice energy LESS negative, so mp DECREASES

Question 5

What is the effect on ionic charge in lattice Enthalpy?

Answer 5

As ionic charge increases, attraction between ions increases, lattice energy becomes MORE negative and more INCREASES.