Buffers
- Created by: Jade S.
- Created on: 13-11-14 19:32
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- 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.
- Acidic Buffers
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