Summary

In this activity, students will view an animation that explores different ways of separating a variety of mixtures. The separation techniques addressed in this animation include filtration, evaporation, distillation, and chromatography (focusing on paper chromatography). Real-world applications as well as particle diagrams of the separation processes are included.

Grade Level

Middle School, High School

Objectives

By the end of this activity, students should be able to:

• Explain how different mixture separation techniques work.
• Interpret particle diagrams representing different separation techniques.

Chemistry Topics

This activity supports students’ understanding of:

• Separating mixtures
• Physical properties

Time

Teacher Preparation: minimal
Lesson: 10-30 minutes

Materials

• Computer and projector with internet access
• https://teachchemistry.org/classroom-resources/separating-mixtures-animation
• Student handout

Safety

• No specific safety precautions need to be observed for this activity.

Teacher Notes

• All of the animations that make up the AACT Animation collection are designed for teachers to incorporate into their classroom lessons. Intentionally, these animations do not have any spoken explanations so that a teacher can speak while the animation is playing and stop the animation as needed to instruct.
• If you assign this to students outside of class time, you can create a Student Pass that will allow students to view the animation (or any other video or ChemMatters article on the AACT website).
  
• We suggest that a teacher pause this animation at several points, including when questions are posed before the answers are revealed, or watch it more than once to give students the opportunity to make notes, ask questions, and test their understanding of the concepts presented. It may be particularly useful to replay the particle diagrams shown with each of the separation techniques. The student activity sheet can help activate students’ prior knowledge, guide them through the animation, and provide a chance for after-viewing reflection.
• The separation techniques presented in this animation progress from less complex to more complex: filtration, evaporation, distillation, and chromatography. Since these are all physical separations of mixtures, it would be helpful if students had a basic understanding of physical properties, such as boiling point and attractions between particles (intermolecular forces), prior to viewing this animation.
• There is another animation on classifying matter in the AACT library that could be used to introduce students to different types of mixtures and pure substances prior to viewing this animation.
• The first couple of questions on the student handout ask them to think about mixtures they’ve encountered in everyday life prior to viewing the animation. This would be a good warmup activity to get the students to activate prior knowledge about mixtures. They could use these questions as a think-pair-share prompt to share thoughts with a peer and the class before viewing the animation.
• The evaporation section of the animation references solar evaporation for harvesting salt from shallow saltwater pools. You can learn more about traditional salt harvesting practices from around the world in this resource from the University of Hawai’i.
• If you happen to have a distillation apparatus available, consider setting it up and allowing students to observe distillation of water + food coloring, orange juice, soda, etc. See some of the labs listed below for distillations students can do themselves with simple equipment set ups.
• In the chromatography section of the animation, there are a number of different types of chromatography listed, most of which students are unlikely to see before college (which is why these are not described in more detail). Khan Academy has a lesson on purification methods that includes readings and videos on more advanced separation techniques, including fractional distillation, column chromatography, thin layer chromatography, and gas chromatography. This lesson might be a useful resource if students are interested in learning more about these advanced techniques.
• Classroom resources from the AACT Library that may be used to further teach this topic include:
  • Animation: Classifying Matter
  • Unit Plan: The Chemistry Basics and Measurement Quick Start Unit Plan
  • Lab: Mixture Separation Challenge
  • Lab: Separation of a Mixture
  • Lab: Distillation of Common Soft Drinks
  • Lab: Using Paper Chromatography to Separate the Pigments Found in Ink
  • Lab: Candy and Leaf Chromatography