1. Acids and Bases
March 8 and 9

2. Pure Water Sometimes something strange happens to water…
One of the hydrogen atoms separates from the molecule
It leaves its electron and just has a proton.
That remaining proton then hooks up with another water molecule.
We then have a hydroxide ion (OH-) and a hydronium ion (H30+)
We usually just abbreviate a hydronium ion H+
Pure Water

3. Rare Occurrence This type of reaction is extremely rare!
At any moment, it happens to only two out of 555 million water molecules.
Rare Occurrence

4. Any substance that increases the concentration of H+ ions in water.
Any solution with a higher concentration of H+ ions than OH- ions is called acidic.
Acids

5. Any substance that increases the concentration of OH- ions in water.
Any solution with a higher concentration of OH- ions than H+ ions is called basic.
Bases

6. The pH scale compares the acidity and basicity of common solutions.
At pH 7 the concentrations of H+ and OH- are equal.
Examples: Pure water (neutral)
As we get closer to 1 we get more acidic.
As we get closer to 14 we get more basic.
pH Scale