Acids and Bases

SC Physical Science Standard PS-3.8 Classify various solutions as acids or bases according to their physical properties, chemical properties (including neutralization and reaction with metals), generalized formulas, and pH (using pH meters, pH paper, and litmus paper).

Acids and Bases Acids produce H + in solutions HCl H + (aq) + Cl - (aq) Bases produce OH - in solutions NaOH Na + (aq) + OH - (aq) H20H20 H2OH2O

Determining pH pH- a measurement of hydrogen ion concentration pH scale ranges from 0 – 14 pH of an acid is 0 – 7 Acids have more H+ than OH-. The lower the pH the more acidic the solution. pH of a base is 7 – 14 Bases have less H+ than OH-. The higher the pH the more basic the solution. pH of neutral is 7 Neutral has equal H+ and OH-. Neutral is neither acid nor base. Water is neutral.

pH is tested for two ways: 1. pH meter- gives a digital reading of the pH of a solution 2. indicator- a compound that turns different colors based on the pH of the solution it is in (example: litmus paper, phenolphthalein)

Properties of Acids -P-Produce H + (H 3 O + ) in solution -F-Formulas start with H - Taste sour -N-Neutralize bases -C-Corrosive to skin and tissue -A-Acids turn litmus paper red

Corrosive to metals -react with metals to produce hydrogen gas Are electrolytes in solution -conduct electricity

Common Acids Acetic Acid - HC 2 H 3 O 2 - Vinegar Folic acid - orange juice

Phosphoric acid - H 3 PO 4 - soda Ascorbic acid - vitamin C - citrus fruits

Hydrochloric acid -HCl - stomach acid Sulfuric Acid -H 2 SO 4 - Car batteries, industry

Properties of Bases -P-Produce OH - in solution -H-Have OH in formula -T-Taste bitter - Neutralize acids -C-Corrosive to skin and body tissues -T-Turn Litmus paper blue

Feel slippery Electrolytes in solution

Common Bases Mg(OH) 2 Magnesium hydroxide antacids NH 3 Ammonia cleaners; fertilizer Ca(OH) 2 Calcium Hydroxide also in fertilizers (lime)

NaOH Sodium hydroxide Drano Al(OH) 3 Aluminum hydroxide Antiperspirants

Acid – Base Neutralization Neutralization- The process of Acids and Bases reacting to form a Salt and Water. This is called neutralization because the in forming water, the H+ and the OH- are equal in solution.