« Back to subjects

# Preliminary chemistry

## Module 3 | Water

### Focus 4: The concentration of salts in water will vary according to their solubility, and precipitation can occur when the ions of an insoluble salt are in solution together

#### Lesson 1 | Precipitation reactions

• Identify some combinations of solutions which will produce precipitates, using solubility data.

• Construct ionic equations to represent the dissolution and precipitation of ionic compounds in water.

• Present information in balanced chemical equations and identify the appropriate phase descriptors (s), (l), (g), and (aq) for all chemical species.

• Perform a first-hand investigation, using micro-techniques, to compare the solubility of appropriate salts in solution through precipitation reactions.

#### Lesson 2 | Modelling solutions

• Describe a model that traces the movement of ions when solution and precipitation occur.

• Identify the dynamic nature of ion movement in a saturated dissolution.

#### Lesson 3 | Concentration

• Describe the molarity of a solution as the number of moles of solute per litre of solution using:

• Carry out simple calculations to describe the concentration of given solutions, given masses of solute and volumes of solution.

• Explain why different measurements of concentration are important.

• Calculate mass and concentration relationships in precipitation reactions as they are encountered.

#### Lesson 4 | Preparing and diluting solutions

• Perform a first-hand investigation to make solutions to specified volume-to-volume and mass-to-volume specifications and dilute them to specified concentrations
(cV = constant)

• ### 60 Lessons

Lessons by expert teachers that cover the NSW Preliminary Chemistry Syllabus comprehensively.

• ### 60 Practice questions

60 lesson quizzes that include a variety of questions. This course also includes 20 focus level and 4 module level tests, as well as a comprehensive end of course practice exam.

• ### 51 Hours of video

Videos that fully explain complex chemistry questions through animation, practical experiments, and tutorials.

• ### 21 Interactive activities

Interactive activities that help you explore and understand key syllabus dot point as well as additional resources such as an interactive Periodic Table.