Solubility rules
Lesson details
Learning outcome
I can remember, and apply, the solubility rules to know whether a salt formed is soluble or insoluble.
Key learning points
- There are a list of general rules which describe the solubility of common types of substances in water.
- Reactions that form insoluble products are called precipitation reactions; the solids formed are called the precipitate.
- When two soluble salts are mixed together, sometimes they will rearrange to create an insoluble salt.
- Solubility rules can be used to identify which two solutions are needed to mix in order to create an insoluble salt.
Keywords
Solubility - The ability of a substance to dissolve in a particular solvent creating a solution; how well a solute dissolves in a solvent.
Salt - An ionic compound, usually formed by neutralisation of an acid by a base.
Soluble - When a substance dissolves in a liquid, it is described as soluble in that liquid.
Precipitate - An insoluble solid formed when two solutions react together.
Insoluble - When a substance does not dissolve in a liquid, it is described as insoluble in that liquid.
Common misconception
All salts are either completely soluble or completely insoluble in water.
Not all salts follow a strict 'soluble' or 'insoluble' rule. Some salts have limited solubility, meaning they dissolve only to a certain extent. Solubility rules help us predict the solubility of common salts, but there are always exceptions.
Teacher tip
Emphasise solubility rules in predicting the outcomes of reactions. Encourage students to refer to solubility tables and charts when planning experiments involving salts. Provide plenty of practice with predicting the products of precipitation reactions and writing equations.
Equipment
Solutions of: AgNO₃, NaCl, BaCl₂, FeCl₂, NaOH, Na₂SO₄, H₂SO₄. CaCO₃ powder, test tubes.
Content guidance
Risk assessment required - equipment
Supervision
Adult supervision required
Licence
except where otherwise stated. See Oak's terms & conditions (Collection 2).Lesson video
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Prior knowledge starter quiz
6 Questions
Q1. What is an ionic compound?
Q2. What is solubility?
Q3.What does the periodic table display?
Q4.What is a chemical reaction?
Q5.What are physical properties?
Q6.What is a mixture?
Assessment exit quiz
6 Questions
Q1.What is solubility?
Q2.What is a precipitate?
Q3.Which ionic compounds are generally soluble?
Q4.What is an exception to the solubility of chlorides?
Q5.What is a precipitation reaction?
Q6.How can solubility rules help in predicting reactions?
To help you plan your 10 chemistry lesson on: Solubility rules, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 10 chemistry lesson on: Solubility rules, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 chemistry lessons from the Making salts unit, dive into the full secondary chemistry curriculum, or learn more about lesson planning.