1. Solutions

2. Forming Solutions Solution Solvent Solute Aqueous solution
A homogeneous mixture
Solvent
The substance that does the dissolving
Solute
The substance that gets dissolved
Aqueous solution
A substance with water as a solvent

3. Solution Composition Saturated Unsaturated Supersaturated
A solution that contains as much solute as will dissolve at that temperature
Unsaturated
A solution in which more solute can dissolve than is dissolved already at that temperature
Supersaturated
A solution that contains more solute than a saturated solution will hold at that temperature

4. Solution Composition continued
Concentrated
A solution in which a relatively large amount of solute is dissolved in a solution.
Dilute
A solution in which a relatively small amount of solute is dissolved in a solution.

5. Factors that Affect the Rate of Dissolving
Three factors that affect the speed of the dissolving process
Surface area
Stirring
Temperature

6. Molarity Sometimes referred to as the concentration of a solution
M = molarity = moles of solute = mol
liters of solution L

7. Adding 1. 0 mole of solute to 1. 0L of water does not make a 1
Adding 1.0 mole of solute to 1.0L of water does not make a 1.0M solution. Why not?

8. Calculating Molarity, I
Calculate the molarity of a solution prepared by dissolving 11.5 g of solid NaOH in enough water to make 1.50 L of solution.
11.5g NaOH 1 mol NaOH =
0.288 mol NaOH =
1.50 L solution
0.288 mol NaOH
40.00 g NaOH
0.192 M NaOH

9. Calculating Molarity, II
Calculate the molarity of a solution prepared by dissolving 1.56g of gaseous HCl into enough water to make 26.8mL of solution.
1.56 g HCL 1 mol HCl =
36.46 g HCl
26.8 mL 1L =
1000 mL
mol HCl = L
mol HCl L
1.59 M HCl

10. Example 15.7
To analyze the alcohol content of a certain substance, a chemist needs 1.00L of an aqueous 0.200M K2Cr2O7 (potassium dichromate) solution. How much solid K2Cr2O7 (molar mass g/mol) must be weighed out to make this solution? 1.00L x 0.200mol K2Cr2O7 = L mol K2Cr2O7 x g K2Cr2O7 = mol K2Cr2O7
0.200 mol K2Cr2O7
58.8 g K2Cr2O7