1. Understanding Solutions
Chapter 7 Section1

2. Solutions
A solution is a homogenous mixture where the components of the mixture are evenly mixed.
Looks uniform: color, density, texture. . .
In a solution, one substance is dissolved into another substance:
Solute: the substance that is dissolved (smaller amount)
Solvent: the substance that is doing the dissolving (larger amount)
Salt Water
Carbonated Water

3. Dissolving
The movement of molecules causes the solute to break apart and mix evenly throughout the solvent. – physical change
Liquids and gases dissolve easily.
Solid alloy solutions must be melted for dissolving to occur.
A liquid dissolves a solid at the surface of a solid.
Since water is a polar molecule, it works well as a solvent. This is why it’s called:

4. Can we reverse dissolving?
Supposed you dissolve a teaspoon of salt into a glass of water. Is it possible to recover the salt from the water?

5. Common Solutions Look at each of these common solutions.
What is the solute? What is the solvent?
How is each one of these solutions formed?

6. Colloids
A colloid is a mixture that contains small, un-dissolved particles that do not settle out.
Small enough to not be seen
Large enough to “scatter light” or give a creamy or opaque texture
Examples: Milk, Gelatin, Mayo, Shaving Cream, Whipped Cream. . .

7. Is Fog/Mist a Solution or Colloid?
What are the two things being mixed?
Are they chemically combined? Or just mixed?

8. Suspensions
A suspension is a mixture in which particles can be seen and easily separated by settling or filtration.
No uniform properties
Visible particles
Examples: Heterogeneous Mixture, Snow Globe, Mud, Oil & Water

9. Compare & Contrast Type of Mixture Does it Settle Out? Particle Size
Does it scatter Light?

10. Ionic and Molecular Compounds
Salt Water – Ionic Compound mixes with Water
Positive and Negative Ions are attracted to the polar water molecules
Conducts electricity
Salt Water Dissolving Link on Moodle!
Sugar Water – Molecular Compound mixes with Water
Polar water molecules attract the sugar molecules and force them apart in the solution, spreading the solute throughout the solvent.
Doesn’t conduct electricity

11. Effects of Solutes on Solvents
Lower Freezing Points
Example: Salt Water (again!)
Pure Water Freezes at _______ ˚F / ________˚C
Salt freezes at a higher/lower temperature
So which freezes first: ocean or lake?
Higher Boiling Points
Example: Coolant
Pure Water Boils at _______ ˚F / ________˚C
Antifreeze boils at a higher/lower temperature
So which is safer for your car: water or coolant?

12. Check your knowledge! Identify each Mixture:
Correctly match the vocabulary words below:

14. The Chemistry of Ice Cream