Buffers

HideShow resource information
  • Created by: Jade S.
  • Created on: 13-11-14 19:32
View mindmap
  • Buffers
    • Acidic Buffers
      • Formed: Weak acid + its Salt e.g. methanoic acid and sodium methanoate
      • When an acid is added: The CH3COOH- ions react with the excess H+ ions, shifting equilibrium to the left so restoring the original concentration of H+.
      • When a base is added: Most of the excess OH- ions react with the H+ ions forming water, shifting equilibrium to the right. OH- also reacts with CH3COOH to form H+ and CH3COO-, shifting equilibrium to the right.
    • Alkaline Buffers
      • Formed: Weak base + its salt e.g. ammonia and ammonium chloride.
      • When a base is added: The OH- reacts with NH4+ ions to form NH3 and water so the [OH-] is restored.
      • When an acid is added: Most of the H+ will react with NH3 to form NH4+ so removes the H+ ions. Some H+ react with OH- to make water, shifting equilibrium to the right so the [OH-] is restored.
    • A solution that can resist changes in pH when a small volume of acid or base is added.
    • Uses of buffer solutions: to calibrate pH meters, hair colouring products, fermentation and in the blood.

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Acids, bases and salts resources »