1. Solution: one substance dissolved in another

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

3. Hydrophilic substances “love water” and dissolve easily

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

5. Concentration: How much solute is dissolved in a unit of solution
The Dead Sea, in the Middle East, has the highest
concentration of salt of any body of water on Earth.
Units: g/L, %, g/mol, ppm etc.
The solubility of a substance measures the maximum amount that can dissolve.
A saturated solution can’t dissolve any more solute.

6. 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?