Soluble salts Flashcards – AQA GCSE Combined Science: Trilogy (8464) — Chemistry — Foundation

What four types of insoluble solid can be reacted with an acid to prepare a soluble salt?

A metal, metal oxide, metal hydroxide or metal carbonate.

How is the insoluble solid chosen when preparing a particular soluble salt from an acid?

Choose a solid that reacts with the acid to make the required salt.

How is the acid reacted with the insoluble solid when preparing a soluble salt solution?

Warm the acid if needed, then add the solid a little at a time until no more reacts.

Why is excess insoluble solid used when preparing a soluble salt solution from an acid?

It ensures all the acid is used up, helping to keep the product pure.

How is the soluble salt solution separated from the excess insoluble solid?

Filter the mixture to remove the unreacted solid, leaving a clear salt solution.

What are the steps for obtaining a pure, dry sample of a soluble salt from its solution by crystallisation?

1. Heat the solution to evaporate some water and concentrate it.
2. Allow the concentrated solution to cool so salt crystals form.
3. Separate the crystals from the remaining solution and dry them.