1. Ch 11: Solution Formation
Solution- a homogeneous mixture
- Can be g & g,
l & l,
s & s,
g & l
l & s
g & s
Miscible-
Immiscible-
(9:46)

2. 11.2 Heat of Solution
The Heat of Solution is the amount of heat energy absorbed (endothermic) or released (exothermic) when a specific amount of solute dissolves in a solvent.
Substance
Heat of Solution
(kJ/mol)
NaOH
-44.51
NH4NO3
+25.69
KNO3
+34.89
HCl
-74.84

3. Steps in Solution Formation
H1 Step 1 - Expanding the solute
Separating the solute into individual components

4. Steps in Solution Formation
H2 Step 2 - Expanding the solvent
Overcoming intermolecular forces of the solvent molecules

5. Steps in Solution Formation
H3 Step 3 - Interaction of solute and solvent to form the solution

6. Predicting Solution Formation
Solvent/
Solute
H1
H2
H3
Hsol’n
Outcome
Polar/
Polar
+ large
- large
+/-small
Solution
forms
Nonpolar
+ small
+/- small
No solution
Nonpolar/
+/-
small
polar

7. Example
Use this data to calculate the enthalpy of hydration for calcium chloride and calcium iodide.
Lattice Energy
Delta Hsoln
CaCl2(s)
-2247 kJ/mol
-46 kJ/mol
CaI2(s)
-2059 kJ/mol
-104 kJ/mol
Ch 11 p. 520, #34
Based on your answer, which ion, Cl- or I-, is more strongly attracted to water?

8. Solubility Chart