PROPERTIES OF WATER

Water:

All processes necessary for life take place in a watery environment.

Water and Hydrogen Bonds

Water is a polar molecule. In water, H’s and O’s do

not give up or receive electrons. Instead they share them

between the atoms. But oxygen ends up being

the more negative side of the molecule

The hydrogens end up being the more positive side of the molecule.

It is like a magnet!

Hydrogen bond: The attraction between

the slightly positive hydrogens and the slightly negative oxygen atoms of a different water molecule .

Or… The slightly negative

side of different molecules that have oxygen or even nitrogen in them.

Properties of Water:

1. Cohesion2. Adhesion3. Dissolving Ionic Compounds

1. Cohesion:

The attraction between molecules of the same substance. So, hydrogen bonding makes water molecules

stick to each other.

1. Cohesion:

Examples: Water forming

beads.

Surface tension: Insects walking on water

2. Adhesion:

The attraction among molecules of different substances. Water molecules will stick to other things.

2. Adhesion:

Examples Water molecules

attracted to the side of a graduated cylinder (meniscus)

Helps plants transport water from their roots to their leaves because water molecules stick to the sides of the vessels in the plant that carry water.

3. Dissolving Ionic Compounds:  Water breaks ionic

bonds so that compounds dissolve in water: Ex. NaCl

It also attracts polar molecules. Polar molecules are more attracted to water than to each other.

Sugar in Plant Sap

Dissolving Ionic Compounds:

Solute The ionic compound getting dissolved Ex: NaCl Na+ and Cl-

Solvent The substance that does the dissolving Ex: Water, H2O

Solution Solute AND solvent Ex: Salt water: NaCl dissolved in water (H2O)

On another note:

Non-polar substances do not dissolve in water. They do not carry a charge so are not attracted to water.

Ex. Water and Oil