8.1 Theory of acids and bases

The role of acids and bases

• Acids and bases are opposites
• Many theories describe how they work

1. Arrhenius Theory of acids and bases
   • Acids produce H⁺ ions, bases produce OH^– ions
   • Neutralization is the process of combining an acid and a base
   • Limitation: weak base ammonia and hydrogen chloride gas could not be explained, as ammonia does not contain OH^–
2. Bronsted-Lowry acids and bases
   • Refer to hydrogen ion as a proton;
   • Acid is proton donor, base is proton acceptor

Conjugate acids and bases

• In a reversible reaction between acid and bases, there are conjugates as well

Amphiprotic species

• Amphiprotic species: Substances which can be both Bronsted-Lowry acids or bases depending on the reaction
  • Examples: