1. Bonds Ionic Covalent Hydrogen

2. Bonds Ionic Transfer electrons Form between ions (+/-) Covalent Share electrons Weaker than ionic 2 types – Polar – Nonpolar

3. Polar Bonds Unequal distribution of charge Water molecule

4. Nonpolar Equal sharing of electrons

5. Hydrogen bonds Attraction between positive hydrogen portion of one molecule… And negative portion of a second molecule Water molecules are bonded by hydrogen bonds

6. Properties of Water Cohesion – Attractive force – Holds together – Due to H-bonding – ex: water sticking to other water molecules-meniscus

7. Properties of Water Surface tension Related to cohesion Due to H- bonds Cause water to be pulled down into liquid “skin” on top of the water Water striders http://www.yo utube.com/wa tch?v=KSLUw mJOo_M http://www.yo utube.com/wa tch?v=KSLUw mJOo_M

8. Properties of Water Adhesion – Attractive force between two different surfaces – Ex: Water molecules and glass molecules

9. Properties of Water Capillary action Raising of liquid Glass tube, water will rise automatically

10. Acids and Bases

11. Acids: Taste sour Contains H+, (the more H+, the stronger the acid) Very reactive

12. Properties of Bases: Taste bitter Contains OH- (the more OH-, the stronger the base) Slippery when wet

13. Acids and Bases If the number of H + ions in a solution is greater than number of OH - ions than the solution is an acid If the OH - ions are greater than the H + ions than the solution is a base

14. pH Scale Ranges from 0-14 Numbers 0-6 represent acids 7 is neutral Numbers 8-14 represent bases 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 strongest acid strongest base

18. pH Scale As you move from pH 0 to pH 14, the concentration of H+ DECREASES (10 times each number) As you move from pH 0 to pH 14, the concentration of OH- INCREASES (10 times each number) Ex: A substance with pH3 is 100 times stronger acid than a substance with pH 5. A substance with pH 8 is 100 times weaker base than a substance with pH 10.

19. Buffer Neutralize acids or bases Keep the pH from large changes