1. Solutions
Do Now:
Special Properties of Water: Decide if each of the examples given is due to
A. Density anomaly B. High melting & boiling points C. Solvent properties D. Polarity
Insects can walk on the surface of water.
Water molecules stick together
Ice forms at 0oC
Ice floats
You can dissolve lots of sugar in water

2. Solution: one substance dissolved in another

3. Solvent: The (liquid) substance that does the dissolving Solute (pronounced Sahl-yoot): The dissolved substance
Solvent
Solute

4. Hydrophilic substances “love water” and dissolve easily

5. Hydrophobic substances “fear water” and don’t dissolve easily

6. Concentration: How much of something is dissolved in solution
The Dead Sea, in the Middle East, has the highest
concentration of salt of any body of water on Earth.
The solubility of a substance measures the maximum amount that can dissolve.
A saturated solution can’t dissolve any more solute.

7. The golden rule: “Like dissolves like”
Solvents are best at dissolving substances that are similar to themselves
Water is polar, and is good at dissolving polar compounds.
Non-polar solvents (like paint thinner or gasoline) are good at dissolving non-polar substances (like tar or oil)
Hydrophilic compounds: polar or non-polar?

8. Homework
Read p. 40
Answer #1 on p. 42