1. Acids and Bases

2. Acids and Bases
An acid is a substance that when added to water increases the concentration (amount) of hydrogen (H+) ions present.
A base is a substance that when added to water increases the concentration (amount) of hydroxide (OH-) ions present.

3. Characteristics of Acids
Acids tend to taste sour
Are corrosive to metals and skin
Contain hydrogen (H+) ions
Turns blue litmus paper red
React with metals and carbonates (CO3-2)
Strong acids conduct electricity when dissolved in water

4. Examples of Common Acids
Hydrochloric acid (muriatic) acid – HCl
Sulfuric Acid (H2SO4)
Acetic Acid (C2H4O2)
Nitric Acid (HNO3)
Citric Acid (C6H8O7)

5. Characteristics of Bases
Bases tend to taste bitter
Feel slippery
Turns red litmus paper blue
Contains hydroxide ions (OH-)
React with fats/oils, so this makes them excellent cleaning agents
Strong bases conduct electricity when dissolved in water

6. Examples of Common Bases
Sodium bicarbonate (Na2CO3)
Sodium hydroxide (NaOH)
Potassium hydroxide (KOH)
Calcium hydroxide Ca(OH)2
Magnesium hydroxide Mg(OH)2
Barium hydroxide Ba(OH)2
Ammonium (NH3)

7. pH Scale
The pH scale measures how acidic or basic a substance is. The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic. A pH greater than 7 is basic.

8. Indicators
An indicator is a substance that helps identify if a substance is an acid or a base by changing colors.  Examples of indicators include: litmus paper, phenolphthalein, pH paper

9. Buffers Cells use buffers in our body to regulate blood pH values.
Buffers resist changes in pH levels
EX: If you exercise for long periods of time, the body uses up available oxygen and produces more carbon dioxide and hydrogen ions
Lactic acid is produced that lowers blood pH
Result: buffers like carbonate take the extra hydrogen ions out of the bloodstream to return pH values to normal