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
Solution: one substance dissolved in another
Solvent: The (liquid) substance that does the dissolving Solute (pronounced Sahl-yoot): The dissolved substance Solvent Solute
Hydrophilic substances “love water” and dissolve easily
Hydrophobic substances “fear water” and don’t dissolve easily
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.
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?
Homework Read p. 40 Answer #1 on p. 42