Acid-Base Equilibria
Chapter 6
, Acids and Bases
• From the earliest days Chemists recognized acids and bases by their
characteristic properties.
• Acids they noticed tasted sour and could change the colour of certain
dyes.
• Bases tasted bitter and felt slippery by touch.
, Acids and Bases (1880’s)
• Arrhenius Theory: Acids when dissolved in water increases H+ ion
concentration, bases when dissolved in water increases OH- ion
concentration.
• H+ ions exist in solution as the H3O+ ion
• Limitation- Restricted to aqueous solutions
ACID
HCl H2O Cl- H3O+
BASE
NH3 H2O NH4+ OH-
, Acids and Bases (1920’s)
• Bronsted-Lowry: Acids are proton donors and bases are proton
acceptors.
• Conjugate acid and base pairs
base Con. acid
HX (aq) + H2O(l) H3O+(aq) + X-(aq)
acid Con. base
Chapter 6
, Acids and Bases
• From the earliest days Chemists recognized acids and bases by their
characteristic properties.
• Acids they noticed tasted sour and could change the colour of certain
dyes.
• Bases tasted bitter and felt slippery by touch.
, Acids and Bases (1880’s)
• Arrhenius Theory: Acids when dissolved in water increases H+ ion
concentration, bases when dissolved in water increases OH- ion
concentration.
• H+ ions exist in solution as the H3O+ ion
• Limitation- Restricted to aqueous solutions
ACID
HCl H2O Cl- H3O+
BASE
NH3 H2O NH4+ OH-
, Acids and Bases (1920’s)
• Bronsted-Lowry: Acids are proton donors and bases are proton
acceptors.
• Conjugate acid and base pairs
base Con. acid
HX (aq) + H2O(l) H3O+(aq) + X-(aq)
acid Con. base
