1. The Extraordinary Properties of Water
Courtesy of Kate Morkeski

2. The extraordinary properties of Water
A water molecule (H2O), is made up of three atoms: one oxygen and two hydrogen. H O 1

3. Hydrogen bonds are very strong and form polar molecules (bond dipoles)
Hydrogen bonds are very strong and form polar molecules (bond dipoles). This is due to the O-H bonds and secondary attractions. (Can also form with N-H and H-F) 10

4. Cohesion 1

5. The extraordinary properties of Water
At sea level, pure water boils at 100 °C and freezes at 0 °C.
Other physical properties include:
Cohesion
Adhesion
High Specific Heat
High Heat of Vaporization
Less Dense as a Solid 1

6. Cohesion
Cohesion is the property of water that causes it to be attracted to itself.
Surface tension, a measure of the strength of water’s surface, is the direct result of cohesion. 1

7. Water strider
The strong film on the surface of water is a result of the attraction between water molecules. This property allows insects to walk on the surface of water and the creation of waves.

8. Adhesion
Water will form strong secondary bonds with other surfaces such as glass, soil, and plant tissues.
Moving water molecules will “tow” each other along. This is called capillary action. This is the same process by which plants and trees remove nutrients from the soil, and paper towels soak up water. . 1

9. “Water vapor forms a kind of global ‘blanket’ which helps to keep the earth warm. Heat radiated from the sun-warmed surface of the earth is
absorbed and held
by the vapor.” 1

10. High Heat of Vaporization
In order for water to evaporate, hydrogen bonds must be broken. As water evaporates, it removes a lot of heat with it.
Thus, the heat of vaporization refers to the amount of energy required to convert water from a liquid to a gas. 1

11. High Heat of Vaporization
Meteostat 5 water Vapor Imagery morning of 9/5/2004
Courtesty of 1

12. Water is Less Dense as a Solid
Which is ice and which is water? The solid form of water is directly related to hydrogen bonds. 1

13. Density of water
If density of object is = to or < than water it will float.
If the object’s volume displaces an amount of water equal to the weight of the object it will float.
Displacement is how steel ships can float even though the density is greater.
Density of pure water is 1.0
Density of pure ice is 0.92.
Density of sea water is 1.03.
Icebergs are made of pure water so they will float with a ratio of more ice above the surface than that of an ice cube.

15. Water and heat transfer…
Specific heat: Heat energy is used to break H-bonds. Specific heat is J/g°C.
Heat of vaporization: amount of energy required to convert 1 gram of a substance from a liquid to a gas and vice versa. Hv = 2260 J/g
Heat of Fusion: amount of energy required to convert 1 gram of a substance from a liquid to a solid and vice versa. Hf = 334 J/g 13