1. Variables that Affect Solubility
Think back to yesterday’s lab…
How does temperature affect the solubility of an M&M?
How does the solvent affect the solubility of an M&M?

2. Polarity and Dissolving
Water is a polar molecule.
Polar: a molecule that is slightly negative on one side and slightly positive on the other side

3. Polarity and Dissolving
Sugar is also polar, so water is attracted to sugar.

4. Let’s act it out How would you describe this solution?
2 people are water molecules
4 people are sugar molecules
Have 4 students act as 2 salt molecules. Put negative sticky notes on 2 of them to represent the Cl ions and positive sticky notes on 2 of them to represent the Na ions. Have the Na and Cl joined in the beginning. Have 2 students act as water, with positive sticky notes on their heads, and negative sticky notes on their feet. Have those 2 water molecules “grab” the appropriate ions and pull them apart. Go to previous slide to illustrate this. There will not be enough water to dissolve all of the salt.
How would you describe this solution?

5. Let’s act it out How would you describe this solution?
8 people are water molecules
4 people are sugar molecules
Have 4 students act as 2 salt molecules. Put negative sticky notes on 2 of them to represent the Cl ions and positive sticky notes on 2 of them to represent the Na ions. Have the Na and Cl joined in the beginning. Have 2 students act as water, with positive sticky notes on their heads, and negative sticky notes on their feet. Have those 2 water molecules “grab” the appropriate ions and pull them apart. Go to previous slide to illustrate this. There will not be enough water to dissolve all of the salt.
How would you describe this solution?

6. What’s actually going on?
So… why you can only dissolve a certain amount of sugar in a certain amount of water?

7. What’s actually going on?
Solubility of sucrose in room temperature water is 3.46g/mL.
This means that in 100 mL of water, I can dissolve ________ of sucrose.

8. Variables that Affect Solubility
Think back to yesterday’s lab…
Why did water dissolve the M&M faster than sugar water?
Why was milk the slowest?