Acids and Bases Overview

Ubiquity and Uses

• Found in foods, soaps, detergents, fertilizers, explosives, dyes, plastics, pesticides, paper.
• Biological significance:
  • Stomachs: very acidic.
  • Blood: slightly basic.
  • Proteins: contain amino acids.
  • Genetic code: bases (A, T, C, G).

Historical Perspective

• Ancient Greeks defined acids and bases by behavior:
  • Acids: tasted sour, corroded metal.
  • Bases: felt slippery, counteracted acids.

Molecular Interactions

• Main Currencies: Protons (hydrogen ions) and electrons.
  • Protons: positively charged.
  • Electrons: negatively charged.
• Molecules may donate or accept protons/electrons.
• Charge Changes:
  • Giving up a proton ~ accepting an electron (becoming more negative).
  • Accepting a proton ~ giving up an electron (becoming more positive).

Strong vs. Weak Acids/Bases

• Strong Acids/Bases:
  • Aggressively donate/accept protons.
  • Strong Acids: all molecules donate protons to water.
  • Strong Bases: rip protons off water.
• Weak Acids/Bases:
  • Donate/accept fewer protons.
  • Reach equilibrium in water.
  • Examples:
    • Vinegar (weak acid).
    • Ammonia (weak base).

Acid-Base Chemistry in Water

• Water acts as acid or base (24-hour molecular ATM).
• Neutralization:
  • Occurs when proton-deposit (acid) and proton-withdrawal (base) balance out.

Conclusion

• Water as a fair and resilient chemical banker.
• Open for transactions without interest or foreclosure.