1. 2.2 Properties of Water

2. The Water Molecule
Water is the only liquid that expands when it freezes
It is a neutral molecule like all others, but has something called polarity

3. The Mickey Mouse Molecule!
Hydrogen
Hydrogen
Oxygen

4. O STRUCTURE OF WATER H H 1 molecule of water is
made up of 2 hydrogen atoms
bonded with 1 oxygen atom

5. The bond that forms water
STRUCTURE OF WATER H H O
The bond that forms water
is a covalent bond

6. Millions of molecules of water make up 1 raindrop

7. Polarity
Because oxygen has 8 protons in the nucleus and hydrogen only has 1, it has a much higher attraction to the electrons
This causes the shared electrons to be closer to the oxygen nucleus
The above cause the H to have a slight positive charge and the O to have a slightly negative
It is now a Polar Molecule

8. + + O H -

9. POLAR MOLECULE THE PROPERTIES OF:
Cohesion, adhesion, specific heat, universal solvent, capillary action, surface tension
ALL HAPPEN BECAUSE WATER IS A POLAR SUBSTANCE!

10. Hydrogen Bonding

11. Cohesion Cohesion is the property of water that causes it to be
attracted to itself.

12. Surface Tension
Surface tension measures the strength of water molecules attracting to one another.
This property allows insects to walk on the surface of water and the creation of waves. 1

13. Surface Tension
Surface tension is the name we give to the cohesion of water molecules at the surface of a body of water

14. Water strider

15. Adhesion
Attraction between molecules of different substances
Ex: glass and water
Capillarity Water molecules will “tow” each other along when in a thin glass tube.

18. Solutions and Suspensions
Mixture – material composed of two or more elements or compounds
Solutions – components are easily distributed throughout the solution (salt and water)
Solute – substance dissolved
Solvent – substance in which substance dissolves
Water is universal solvent
Suspensions – mixture of water and nondissolved material

19. Suspension
Solution

20. pH Scale Indicates the number of H+ ions
Acid – a solution that contains excess H+ ions
Base – a solution that contains excess OH- ions
Buffer – weak acids and bases that can react with strong acids or bases to prevent sharp, sudden changes in pH