CLAW At-Home Experiment: Colligative Properties
At a Glance
Discipline
- Chemistry
- STEM
Instructional Level
- College & CEGEP
- University
Course
- Chemistry of Solutions
Tasks in Workflow
Social Plane(s)
- Individual
Type of Tasks
- Analyzing
- Writing
- Experimenting & conducting inquiry
Technical Details
Useful Technologies
- Equipments (e.g., thermometer, containers, tubes)
Class size
- Medium (50-99)
Time
- Single class period (< 90 mins)
Instructional Purpose
- Exploration & inquiry
Overview
In this CLAW (Chemistry Laboratory Alternative Work) At-Home experiment, students will perform an experiment using household chemicals and materials. It was designed as a substitute for in-person laboratories, usually performed at the college level, during the COVID-19 pandemic. However, it may also be used as an experiment that students can carry out in the lab or for student projects.
Instructional Objectives
Colligative properties of solutions depend on the quantity of solute dissolved in the solvent rather than the identity of the solute. The phenomenon of freezing point lowering will be examined quantitatively as an example of a colligative property in this at-home experiment.
Workflow & Materials
Activity Workflow
Contributor's Notes
Benefits
Challenges
Tips
Benefits
- This hands-on home experiment is an engaging way to manipulate and measure chemical compounds outside an official laboratory set-up;
- Experimental data recorded by the students can be analyzed to perform calculations and write a complete lab report.
Challenges
- It may be difficult to estimate the time needed for students to complete this activity at home.
- Gathering of chemicals and material usually carried out by a technician must be done by each student.
Tips
- The list of chemicals and material necessary for the experiment should be given to students as soon as possible to make sure they have the time to purchase and gather the needed items;
- Equipment could be loaned out to the students from the college;
- Volume measurements can be done with measuring spoons/cups, although they may be less accurate than syringes;
- Container for ice/salt bath could be a Pyrex measuring cup or a food thermos, or any container large enough to hold the ice/salt bath and polypropylene tube. It should be big enough so that when the tube is immersed into the ice/salt bath, the liquid level inside the tube is below the level of the ice/salt mixture;
- If sugar solutions do not dissolve immediately, leave them out to dissolve over several hours (ideally prepare and let dissolve overnight). Do not heat them as you will lose some of the water by evaporation;
- If the ice/salt bath level is lower than the liquid in the polypropylene tube, add more ice/salt to the bath;
- Make sure you clean the polypropylene tube with warm water to dissolve and melt the frozen sucrose solution before moving on to the next sample;
- The higher the concentration of the sucrose, the longer it takes to freeze. It may take up to 30 min to complete the measurements of the most concentrated solutions. Alternatively, you may place the higher-concentration solutions in the fridge to cool down before performing the experiment to reduce the run time.
Additional Contributors
- Carmen Leung, Dawson College
- Nadia Schoonhoven, Dawson College
Applied Strategies
Published: 16/07/2020
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