1. Which are solutions?

2. Solutions A. A solution is a uniform mixture of substances. 1. Types of solutions: solid in liquid: NaCl in water  Na +, Cl -, H 2 0 gas in gas:Air (N 2, O 2, Ar, etc) solid in solid:Bronze (Cu and Sn) = an alloy gas in liquid:CO 2 in H 2 O liquid in liquid:alcohol in H 2 O liquid in solid:Hg in Ag

3. 2. solute: substance being dissolved the smaller amount solvent: dissolves the solute the greater amount Ex. solution solutesolvent salt water air NaClwater O2O2 N2N2

4. 3. The most common solvent: water Water solutions are called aqueous (aq) Ex: In water: NaCl(s)  Na + (aq) + Cl - (aq) solidwater

5. Water H 2 O is polar. It has a + and – side: H H O ++ - Attracts + charges + - Attracts - charges NaCl dissolves because: + - + - Na Cl

6. Ex. Surface tension occurs because water molecules attract each other.

8. Oil is nonpolar.  H 2 O cannot pull it apart.  It does not dissolve in water. Olive oil: Diesel oil: Pentane:

9. Oil slicks

10. Rule: Likes dissolve likes: 1. Polar substances dissolve polar ones. Ex. NaCl in water 2.Nonpolar substances dissolve nonpolar ones. Ex. Oil in turpentine 3. Nonpolar ones do NOT dissolve nonpolar ones. Ex. Water does not dissolve oil.

11. 4. An electrolyte conducts electricity in a solution because the solute is ions. Ex: Na + and Cl - are charged. They conduct.

12. Which solution contains electrolytes?

13. 4. An electrolyte conducts electricity in a solution because the solute is ions. Ex: Na + and Cl - are charged. They conduct. Non-electrolyte: solution does not conduct electricity. Ex: Sugar (C 6 H 12 O 6 ) is not charged.

14. It’s what plants crave. http://www.youtube.com/watch?v=e1fKzw05Q5A

16. 5. Particles in solution are too small to filter out, but they can be separated by other physical means. Ex Desalination of sea water by distillation When salt water is boiled, the salt remains. The pure water can be condensed and used.