Strong vs Weak Bases
Chemistry: Cambridge International GCSE Supplement, topic 7.1.10
Strong vs Weak Bases
Bases are metallic oxides or hydroxides (or ammonia) that neutralise acids to form salt and water. There are two types: soluble and insoluble bases. An alkali is a soluble base - one that dissolves in water.
Strong base
- Aqueous sodium hydroxide and potassium hydroxide are examples of strong bases.
- Strong bases fully ionise in aqueous solutions.
- NaOH(aq) → Na+(aq) + OH-.
- KOH(aq) → K+(ap) + OH-.
Weak base
- Weak bases don't fully ionise in aqueous solutions.
- Ammonia solution is an example of a weak base.
- It exists mainly as NH3 molecules. Only a few of these react with water molecules to form ions.
- NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH-(aq).
Test yourself on Strong vs Weak Bases
Which of these are examples of strong bases?
Which of the following is a weak base?