Summary
Salts are formed through various methods depending on their solubility, such as using acids with metals, bases, or alkalis. Soluble Salt — a salt that dissolves in water. Example: Sodium chloride can be prepared by reacting hydrochloric acid with sodium hydroxide. Insoluble Salt — a salt that does not dissolve in water. Example: Barium sulfate can be prepared by mixing solutions of barium chloride and sodium sulfate. Water of Crystallisation — water molecules that are part of the crystal structure of a salt. Example: Copper(II) sulfate pentahydrate contains water of crystallisation.
Exam Tips
Key Definitions to Remember
- Soluble Salt
- Insoluble Salt
- Water of Crystallisation
Common Confusions
- Confusing soluble and insoluble salts
- Misunderstanding the role of water of crystallisation
Typical Exam Questions
- How do you prepare a soluble salt using an acid and a metal? Add excess metal to acid, filter, and evaporate the solution.
- What is the method to prepare an insoluble salt? Mix two soluble salts to form a precipitate, then filter and dry it.
- What is water of crystallisation? Water molecules that are part of the crystal structure.
What Examiners Usually Test
- Understanding of solubility rules
- Ability to describe preparation methods for different types of salts