1. Chapter 2 Section 2 Properties of Water

2. The Water Molecule… The chemical symbol for water is H20.
This means the molecule consists of 1 Oxygen atom and 2 Hydrogen atoms.
The Oxygen and Hydrogen atoms share electrons.
The Oxygen shares one electron with each hydrogen atom.
Thus water is a covalent molecule.

3. The Water Molecule… A water molecule is considered to be Polar.
A polar molecule is a molecule in which the charges are unevenly distributed.

4. The Water Molecule…
Because water molecules are polar they can attract each other.
These attractive forces are called hydrogen bonds.
They are not as strong as covalent or ionic bonds.
A single water molecule can be involved in up to 4 hydrogen bonds at the same time.
The attraction between molecules of the same substance is called cohesion.
When molecules of different substances are attracted that is called adhesion.

5. Solutions and Suspensions…
A mixture is a material composed of two or more elements or compounds are physically mixed but not chemically combined.
Water can form two types of mixtures.
Solutions
Suspensions

6. Solutions and Suspensions…
Solutions are mixtures whose components are evenly distributed thourghout.
Solutes are the substances being dissolved.
Solvents are the substances in which the solute is dissolved.

7. Solutions and Suspensions…
Suspensions are mixture of water and undissolved solids.

8. Acids, Bases, and pH…
The pH scale is a measurement system used to indicated the concentration of H+ ions in a solution.
The pH scale ranges from 0 to 14.
Acids are compounds that form H+ ions in a solution.
They are located on the pH scale at values under 7.
Strong acids are usually found between 1 to 3
Bases are compounds that produce OH- ions in solution.
They are located on the pH scale at values over 7
Strong bases are usually found between 11 to 14.

9. Acids, Bases, and pH…
Buffers are weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH.
They are an important part of homeostasis.