Summary: Mixtures, including solutions, contain a combination of pure substances that can be separated using a range of techniques.
Solute, Solvent, Solution
“describe the importance of water as a solvent in daily life, industries and the environment”
“describe aqueous mixtures in terms of solute, solvent and solution”
Notes
| Activity/Resource | Notes |
|---|---|
| [Practical] Creating Mixtures | Students can either create or investigate different everyday mixtures (created by combining solids, liquids and/or gasses together into solutions, colloids or suspensions), e.g. – Air (gas/gas) – Hair spray (gas/liquid) – Ice cloud (gas/solid) – Whipped cream (liquid/gas) – Milk/mayonnaise (liquid/liquid), etc. Care needs to be taken to distinguish mixtures from compounds (provide clear definitions and examples + counterexamples). Significant attention should be given towards distinguishing substances (in mixtures) as either solutes or solvents (e.g. sugar dissolved in water) |
| [Practical] Fireworks in a Beaker | More details of this practical by Biotechie, including an explanation + suggestions for modifications, can be found on the Science Aces website |
Separation Techniques
“relate a range of techniques used to separate the components of some common mixtures to the physical principles involved in each process, including filtration, decantation, evaporation, crystallisation, chromatography and distillation”
“investigate the application of a physical separation technique used in everyday situations or industrial processes, eg water filtering, sorting waste materials, extracting pigments or oils from plants, separating blood products or cleaning up oil spills”
“research how people in different occupations use understanding and skills from across the disciplines of Science in carrying out separation techniques”
Notes
| Activity/Resource | Notes |
|---|---|
| [Practical] Separation Challenge | Prepare mixtures that require a range of separation techniques to separate out each component (e.g. salt, sand and iron mixed together) In groups, students work together to use the lab equipment available to separate out each of the components. Students should record their steps + justifications. Alternatively, this activity can be conducted as a demonstration, with students contributing suggestions (+ justifications) for separation techniques It may be beneficial to start off with demonstrations that require only one technique (e.g. separating rocks of different sizes using a sieve) |
| [Practical] Investigation | Provide students different examples of separation apparatus + different types of mixtures (e.g. salt dissolved in water, water and mud, water and oil) As a class, hypothesise + have students perform tests to determine the types of mixtures each separation technique is most effective for. Optionally, have students use whiteboards to sketch out their explanation |
| [Practical] Chromatography Test | Context: Crime Solving/Forensics Before class, create a ‘ramson note’ written in black marker pen. Collect a set of other black (washable) markers from each ‘suspect’ (different brands). As a class or in groups (depending on how much effort you want to put in), conduct a chromatography test using the four markers, and compare with a sample from the ‘crime scene’ (i.e. cut a section from the note) Note: this is a common science experiment for demonstrating chromatography. As such, you can find experiment details + suggestions online, e.g. on Webinnate or MnSTEP |
| [Practical] Water Filter | In groups, students construct something similar to this (requires a lot of preparation to gather the main materials: rocks, coarse sand, charcoal, fine sand, cloth) Can test ‘muddy’ water (preferably made in the lab rather than collected) Note for students: if they were to use this to filter water, they would still need to boil the water before drinking Activity: students can hypothesise/test what parts are being filtered out at each stage Students can also compare their water filter to wastewater treatment facilities |
*Will continue adding/refining ideas here over time.
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