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Separation of a Mixture (8 Favorites)

LAB in Separating Mixtures, Physical Change. Last updated June 4, 2018.


Summary

In this lab, students devise their own method to separate a mixture of sand, salt, poppy seeds, and iron filings.

Grade Level

High or middle school

Objectives

By the end of this lesson, students should be able to

  • identify physical properties of each of the four substances.
  • identify appropriate methods for separating mixtures.

Chemistry Topics

This lesson supports students’ understanding of

  • Separating mixtures

Time

Teacher Preparation: 1 hour

Lesson: two 55-minute periods

Materials

For each group:


  • Mixture
  • Sand
  • Salt
  • Poppy seeds
  • Iron filings
  • Petri dishes/
    watch glasses/
    evaporating dishes
  • Funnels
  • Tape
  • Plastic wrap
  • Test tubes
  • Rubber stoppers
  • Aluminum foil
  • Wood splints
  • Spatulas
  • Scoopulas
  • Strainer
  • Pipets
  • Filter paper
  • Forceps
  • Paper towels
  • Paper clips
  • Distilled water
  • Magnets
  • Hot plate
  • Beakers
  • Erlenmeyer flasks
  • Wash bottles
  • Drying oven

Safety

  • Always wear safety goggles when working with chemicals in a laboratory setting.
  • Use caution and wear protective equipment when working with hot objects.

Teacher Notes

  • The mixture should contain approximately equal amounts of each of the four substances.
  • Be sure to measure the exact amount of each substance included in each group’s mixture so that you know which group was closest to 100% separation.
  • Encourage students to experiment with the test mixture and the individual components before attempting to separate their actual mixture

For the Student

Lesson

Background

Separation and recovery of pure substances are extremely important operations of scientific research and industry, but separating the different components in a mixture can often prove quite challenging. In this investigation, you will have an opportunity to design, develop, and implement your own (with a partner) procedure in an attempt to separate and recover the components of a mixture. The mixture contains the following four substances in dry granular forms: salt, sand, iron filings, and poppy seeds.

The team that gets closest to a 100% recovery of each component will win a prize.

Materials


  • Mixture
  • Sand
  • Salt
  • Poppy seeds
  • Iron filings
  • Petri dishes/
    watch glasses/
    evaporating dishes
  • Funnels
  • Tape
  • Plastic wrap
  • Test tubes
  • Rubber stoppers
  • Aluminum foil
  • Wood splints
  • Spatulas
  • Scoopulas
  • Strainer
  • Pipets
  • Filter paper
  • Forceps
  • Paper towels
  • Paper clips
  • Distilled water
  • Magnets
  • Hot plate
  • Beakers
  • Erlenmeyer flasks
  • Wash bottles
  • Drying oven

Procedure

It’s all in your hands. Brainstorm with your partner how you will separate the mixture. Consider the materials available to you. What do you need to know about each of the components before you decide how to separate them? How can you find these things out? If you need to do any preliminary testing, do it before beginning the actual separation.

Before you can begin, you will need a preliminary procedure. You can write it in step-by-step form, in a flow chart form, or using pictures. While you actually perform the separation, you will need to document exactly what you do. This will be more detailed than your initial procedure and in a step-by-step format.

You will need to determine the final masses of the products you collect so your teacher can determine how close to 100% recovery you are.

Analysis Questions

  1. How successful were you (on a scale of 1-10) in separating and recovering each of the four components? Justify your success based on your observations/data.
  2. For each of the four components, describe the specific physical property that enabled you to separate it from the rest of the mixture.
  3. What made you decide to do your procedure steps in the order in which you did them? Would any order have worked? Explain.
  4. If you could do the lab over again, what specific things would you do differently? Explain.
  5. What two materials or tools that weren’t available may have made your separation easier?