1. ACIDS & BASES
(pH)

2. ACIDS
Compounds that release a large number of H+ (hydronium ions) in water
The more H+, the stronger the acid
Taste sour

3. Bases
Compounds that release a large number of OH- (hydroxide ions) in water
The more OH-, the stronger the base
Taste bitter, feel slippery

4. pH Scale—measures the strength of an acid or base
Acids and bases are important to living organisms to maintain their “bodily” processes
pH Scale—measures the strength of an acid or base
Measures the H+ ion concentration.
Spans from 0 to 14 7 14
ACIDS
BASES
NEUTRAL
Strong
Weak

5. Indicators—a special type of compound that changes color as the pH of a solution changes, thus telling us the pH of a solution.

6. Litmus—only tells if acid or base, not how strong
Turns red in acid
Turns blue in base
pH paper—will tell strength of acid or base
Turns different colors that match to a number

7. Humans (& other organisms) have many areas of body with different pH levels
blood = slightly basic
Stomach acid and urine= acidic
Living organisms are very sensitive to changes in pH.
Enzymes can function only at very specific pH’s