5.2.1 (c-d)

Question 1

Define enthalpy change of solution

Answer 1

Enthalpy change when 1 mole of a solute dissolves in a solvent (water)

• Can be exothermic or endothermic

Question 2

Define enthalpy change of hydration

Answer 2

Enthalpy change when 1 mol of gaseous ions dissolves in water to form 1 mol of aqueous ion

E.g. Na⁺_(g) + aq → Na⁺_(aq)

(aq represents excess water)

• Always exothermic

Question 3

Describe the process of dissolving

Answer 3

1. Ionic lattice breaks up (opposite to lattice enthalpy)
2. Separate gaseous ions interact with polar water molecules forming hydrated aqueous ions
   
   • This is the enthalpy change of hydration

Question 4

What is the difference between Born-Haber Cycles where Enthalpy Changes of Solutions can be exo or endo?

Answer 4

Question 5

Construct a Born Haber Cycle for Enthalpy changes in Solution

Answer 5