1. The Nature of Solutions
Ch. 12- Solutions
C. Johannesson

2. A. Definitions Solute - substance being dissolved
Solution - homogeneous mixture
Solute - substance being dissolved
Solvent - present in greater amount
C. Johannesson

3. B. Solvation HNO3(aq) + H2O(l)  H3O+(aq) + NO3–(aq) Ionization
breaking apart of some polar molecules into aqueous ions
HNO3(aq) + H2O(l)  H3O+(aq) + NO3–(aq)
C. Johannesson

4. B. Solvation NaCl(s)  Na+(aq) + Cl–(aq) Dissociation
separation of an ionic solid into aqueous ions
NaCl(s)  Na+(aq) + Cl–(aq)
C. Johannesson

5. Making solutions
Whether the solute and the solvent are polar, nonpolar, or ionic determines
How much will dissolve.
Whether a substance will dissolve.

6. How Much? Dissolved particles are surrounded by solvent particles
Eventually solvent particles are all occupied
Begin turning back to solid
Equilibrium reached where dissolved particles are turning to solid as fast as solid is being dissolved
No more will dissolve

7. How Much?
Solubility- The maximum amount of substance that will dissolve at that temperature (usually g/L).
Saturated solution- Contains the maximum amount of solid that can be dissolved.
Unsaturated solution- Can dissolve more solute.
Supersaturated- A solution that is temporarily holding more than it can, a seed crystal will make it come out

8. C. Solubility UNSATURATED SOLUTION more solute dissolves
no more solute dissolves
SUPERSATURATED SOLUTION
becomes unstable, crystals form
concentration
C. Johannesson

9. C. Solubility Solubility Curve
shows the dependence of solubility on temperature
C. Johannesson

10. Practice Problems
How many grams of potassium nitrate can dissolve in 100 g of water at 500C?
At 200C, a solution contains 120 g of NaNO3 in 100 g of water. Is this solution saturated, unsaturated, or supersaturated?
You need to make a solution containing 150 g of potassium chloride in 300 g of water. What temperature is required?

11. Liquids Miscible means that two liquids can dissolve in each other.
Immiscible means they can’t

12. Why does Italian dressing separate?
A) Oil and vinegar are immiscible
B) Oil is nonpolar and vinegar polar
C) Vinegar particles are attracted to themselves more than they are attracted to the oil particles.
D) All of the above