1. Justify – TPS
Why do some things dissolve in water, but other things do not?

2. Lecture 4.2 – The Dissolving Process and the Rate of Dissolving

3. Today’s Learning Targets
LT 4.1 – I can discuss how ionic solids dissolve due to the random molecular motion of the water molecules.
LT 4.3 – I can compare and contrast various intermolecular forces and relate them to the dissolving process of a solid.
LT 4.4 – I can hypothesize how surface area, temperature, and pressure impact the dissolving process of a solid.

4. Why do substances dissolve?

5. I. The Dissolving Process
The dissolving process is facilitated by motion of liquid molecules and intermolecular forces.
Liquid molecules are moving in random motion.
When a molecule is dissolved in water, water molecules hydrogen bond with one another to form a cage to dissolve.

6. How does salt dissolve water? clip

8. II. Like Dissolves Like Like substances dissolve like substances
If something has a charge, then it will not be able to dissolve something that does not have a charge.

9. Summarize

10. Cools down to room temperature
A Problem
Cools down to room temperature
Gross! 

11. Justify – TPS
Why does this solid appear at cold temperatures, but it wasn’t present when the cider was hot?

12. Sugar Cube Investigation
We can make statements about what we think is the answer to a question, but a good scientist experiments
You are going to be doing an investigation with your group to determine how surface area and temperature impact the rate at which something dissolves.

13. Lab Conduct Follow the procedure that has been given to you
Respect the equipment. It costs a lot of money to replace this stuff
Use the chemicals in a responsible and safe way
Clean up the space when you are done
Read the steps, they will tell you what to do.

14. Lab Work Time

15. Lab Debrief
What happens to the rate at which the sugar dissolved as you increased the temperature?
What happens to the rate at which the sugar dissolved as you increased the surface area?
Why?!?!?!

16. How does temperature, pressure, and surface area impact rate of dissolving?

17. I. Dissolving We can alter the rate at which the solute dissolves by:
1. Changing the temperature
2. Changing the surface area of the solute
3. Changing the pressure of the solution.

18. II. Temperature and Dissolving
As you increase the temperature, molecules start moving faster.
By moving faster, the molecules are better able to grab the solute, form the cages around them and pull them into the solution.
Therefore, the faster molecules are moving, the faster something dissolves.

19. Remember What Dissolving Looks Like?

20. Temperature and Dissolving Rate
Cold liquid
Hot liquid

21. III. Surface Area and Dissolving
As you increase the surface area, the rate at which the solute dissolves increases.
As you increase the surface area of a substance, you are providing more sites for the solvent to interact with the solute.

22. Surface Area and Dissolving

23. Making a Carbonated Beverage
Open a soda to demonstrate that carbonation is induced

24. Justify – TPS
Why does your soda become carbonated when you open it? What is happening?

25. IV. Pressure and Dissolving
As you increase the pressure, the rate at which the solute dissolves increases.
The solubility and pressure relationship is clearly seen when a gas dissolves in a liquid.
Gases can dissolve into liquids.

26. IV. Pressure and Dissolving
When a gas is above a liquid and the pressure is increased, the gas molecules collide more often with the wall of the liquid and this causes more gas to be pushed into the liquid.

29. Summarize