1. Solutions

2. Classification of Matter
Solutions are homogeneous mixtures

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

4. Solute Solvent A solute is the dissolved substance in a solution.
Salt in salt water
Sugar in soda drinks
Carbon dioxide in soda drinks
Solvent
A solvent is the dissolving medium in a solution.
Water in salt water
Water in soda

5. Soluble and Insoluble Soluble: when a solute dissolves in a solvent
Insoluble: When a solute doesn’t dissolve in a solvent

7. B. Solvation First... Then... Solvation – the process of dissolving
solute particles are surrounded by solvent particles
First...
solute particles are separated and pulled into solution
Then...

8. Solvents
Solvents at the hardware store

9. Saturation of Solutions
A solution that contains the maximum amount of solute that may be dissolved under existing conditions is saturated.
A solution that contains less solute than a saturated solution under existing conditions is unsaturated.

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

12. Concentrated vs. Dilute

13. Concentrated and Dilute
A concentrated solution contains more solute than solvent
A dilute solution contains more solvent than solute

14. Dissolution of sodium Chloride

15. Solubility Trends
The solubility of MOST solids increases with temperature.
The rate at which solids dissolve increases with increasing surface area of the solid.
The solubility of gases decreases with increases in temperature.
The solubility of gases increases with the pressure above the solution.

16. Therefore… Solids tend to dissolve best when: Heated Stirred
Ground into small particles
Gases tend to dissolve best when:
The solution is cold
Pressure is high

17. Calculations of Solution Concentration
Concentration - A measure of the amount of
solute in a given amount of solvent or solution
Grams per liter - the mass of solute divided by the volume of solution, in liters
Molarity - moles of solute divided by the volume of solution in liters
Parts per million – the ratio of parts (mass) of solute to one million parts (mass) of solution
Percent composition - the ratio of one part of solute to one hundred parts of solution, expressed as a percent

18. Molarity
The concentration of a solution measured in moles of solute per liter of solution.
mol = M L

19. Calculating the molarity
If you have 2 moles of glucose in 8 liters of solution what is the molarity of the solution?
Molarity= moles per liter
Molarity = 2moles / 8 liters
=0.25 M

20. Calculating the molarity
2) If you have 6 moles of glucose in 4 liters of solution what is molarity of this solution?
3) If water is added to 2 mol of glucose to give 5L of solution what is its molarity?
4) A salt solution has a volume of 250ml and contains 0.70mol of NaCl. What is the molarity of the solution?

21. Calculating the molarity
Molarity = moles/liter
In the problem we have 250 ml of solution
Convert this to liters
250ml/1000ml =0.250L
Now calculate the molarity
0.7mol = 2.8 M
0.250L

22. Calculating the molarity
A saline solution contains 0.90 g of NaCl per 100 ml of solution. What is its molarity?
Molarity is moles per liter. Convert the concentration to moles per liter.
Start with the gram formula mass of NaCl
23.0g+35.5g=58.5g

23. Molarity contn Now calculate the moles of NaCl
We know mole NaCl contains 58.5g
How many moles would be present in 0.90g
0.90 x 1.0mole = mole
58.5 g
Now convert mol per 100ml to mol per liter
Molarity=Moles/liter=0.015/0.1000= 0.15M

24. Calculating grams of solute
How many grams of solute are present in 1.5L of 0.20M Na2SO4?
Rearrange the equation
Liters of solution x molarity =moles of solute
Substitute the known in the equation
1.5L x 0.20 =0.30 mol

25. Calculation contn
To determine the weight of solute, multiply the number of moles of Na2SO4 by its mass
1.0 mol contains 142.1g
0.30mol will contain ?
0.30 x 142.1g = 42.6 g
1.0 mol