acids and bases

Study Guide: Acids and Bases

Definitions:

• Acid: A substance that releases hydrogen ions (H⁺) when dissolved in water.

• Base: A substance that accepts hydrogen ions or releases hydroxide ions (OH⁻) in solution.

Properties:

Acids:

• Sour taste (e.g., citric acid in lemons).

• Conduct electricity in solution.

• React with metals to produce hydrogen gas.

• Turn blue litmus paper red.

Bases:

• Bitter taste (e.g., baking soda).

• Slippery feel (e.g., soap).

• Conduct electricity in solution.

• Turn red litmus paper blue.

pH Scale:

• Ranges from 0 to 14.

  • pH < 7: Acidic

  • pH = 7: Neutral (pure water)

  • pH > 7: Basic (alkaline)

Common Examples:

• Acids: Hydrochloric acid (HCl), sulfuric acid (H₂SO₄), citric acid.

• Bases: Sodium hydroxide (NaOH), ammonia (NH₃), calcium carbonate (CaCO₃).

Neutralization Reaction:

• An acid reacts with a base to form water and a salt.

  • Example: HCl + NaOH → NaCl + H₂O

Applications:

• Acids: Used in batteries, food preservation, and cleaning agents.

• Bases: Used in soap making, baking, and cleaning products.

Indicators:

• Substances that change color based on pH (e.g., litmus paper, phenolphthalein, pH meter).

Key Concepts:

• Brønsted-Lowry Theory: Defines acids as proton donors and bases as proton acceptors.

• Lewis Theory: Acids are electron pair acceptors, and bases are electron pair donors.

Safety Precautions:

• Always handle acids and bases with care.

• Use gloves and goggles when conducting experiments involving acids or bases.