1. Water and Aqueous Systems Chemistry Mrs. Coyle

2. The Water Molecule Bent Two lone electron pairs Polar molecule

3. Hydrogen Bonding: The intermolecular forces in which hydrogen that is covalently bonded to a very electronegative atom is also weakly bonded to an unshared electron pair of another atom (N, O, F).

5. Hydrogen bonding is responsible for many of the unique properties of water such as: high surface tension having a low vapor pressure having a lower density in the solid form than in the liquid form.

6. Surface tension causes water to form nearly spherical droplets.

7. http://www.chemistryland.com/CHM107/Water/WaterBeadsOnPlantPlusWaterCharge.jpg

9. Surface Tension  Surface tension is an inward force that causes the surface to behave as a skin.  The higher the intermolecular forces the greater the surface tension.

10. Surface Tension of Water http://quest.nasa.gov/space/teachers/microgravity/image/66.gif

11. Water – Mercury

12. Surfactants: Substances that interfere with the hydrogen bonding between molecules and reduce the surface tension. Cause spreading or wetting. Examples of surfactants are soaps.

13. Water’s Low Vapor Pressure Because of the hydrogen bonds holding the water molecules together, the molecules have a low tendency to break free from the surface into the vapor phase.

14. Water has a relatively high boiling point. Why?

15. Density of Water Ice has a lower density than liquid water. Maximum density of water happens at 4 O C.

16. Density of Water

19. Ice- (Honeycomb Shape)