PROPERTIES OF WATER

• Polar molecule

• Cohesion and adhesion

• High specific heat

• Density – greatest at 4 C

• Universal solvent of life

Properties of Water

negative

The oxygen end “acts” —

positive

The hydrogen end “acts” —

hydrogen bond

The slightly negative regions of one molecule are attracted to the slightly positive regions of nearby molecules, forming a —

4

Each water molecule can form a maximum of — hydrogen bonds

Cohesion

• Attraction between particles of the same substance ( why water is attracted to itself)

• Results in Surface tension (a measure of the strength of water’s surface because of H-bonds)

• Produces a surface film on water that allows insec water

Surface tension

a measure of the force necessary to stretch or break the surface of a liquid, is related to cohesion.

Adhesion

• Attraction between two different substances.

• Water will make hydrogen bonds with other surfaces such as glass, soil, plant tissues, and cotton.

Capillary action

action-water molecules will “tow” each other along when in a thin glass tube.

• Example: transpiration process which plants and trees remove water from the soil, and paper towels soak up water.

Cohesion

• responsible for the transport of the water column in plants

• among water molecules plays a key role in the transport of water against gravity in plants

Adhesion

• clinging of one substance to another, contributes too, as water adheres to the wall of the vessels.

High Specific Heat

Amount of heat needed to raise or lower 1g of a substance 1° C.

High Heat of Vaporization

Amount of energy to convert 1g of a substance from a liquid to a gas

cooling effect

As water evaporates, it removes a lot of heat with it

Suspensions

• don’t dissolve but separate

• Water keeps the pieces suspended