Chemistry Acids, Bases, and pH

The pH Scale

• The pH scale measures hydrogen ion (H+) concentration in a solution.
• It ranges from 0 (highly acidic) to 14 (highly basic).
• A pH of 7 is considered neutral; pure water has this pH.
• Solutions with pH below 7 are acidic, indicating higher H+ ion concentrations.
• Solutions with pH above 7 are basic, indicating lower H+ ion concentrations.

Acids

• Acids are compounds that release H+ ions when dissolved in a solution.
• Acidic solutions have a higher concentration of H+ ions compared to pure water.
• Acids are characterized by a pH lower than 7.
• Common examples include lemon juice, tomato juice, carbonated beverages, and vinegar.

Bases

• Bases are compounds that generate hydroxide ions (OH–) in a solution.
• Basic solutions have a lower concentration of H+ ions relative to pure water.
• Bases exhibit a pH higher than 7.
• Notable examples include ammonia, soaps, bleach, and sodium bicarbonate.

Buffers

• Human cells typically maintain a pH between 6 and 8 for optimal functioning.
• Deviations in pH can impede essential chemical reactions within cells.
• It is crucial for cells to regulate their pH levels.
• Buffers are biological substances that help stabilize pH, preventing rapid changes.