Summary

In this lab, students will separate iron filings from iron-fortified breakfast cereals. Students will use the recorded data to conduct percent composition calculations.

Grade Level

High or Middle School

Objectives

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

• Successfully separate a mixture.
• Collect data using an electronic scale.
• Determine percent composition of components in a mixture.

Chemistry Topics

• Mixtures
• Separating Mixtures
• Percent Composition

Time

Teacher Preparation: 20 minutes

Lesson: 60 minutes

Materials

• Iron-fortified breakfast cereals (one “healthy” and one “kids” cereal – suggestions below)
• 400-mL beaker
• Distilled water
• Magnetic stirrer with a stirring bar or another strong magnet
• Electronic balance (two-decimal reading is recommended)
• Weighing boat
• Mortar and Pestle

Safety

• Always wear safety goggles when handling chemicals in the lab.
• Students should wash their hands thoroughly before leaving the lab.
• When students complete the lab, instruct them how to clean up their materials and dispose of any chemicals.
• Food in the lab should be considered a chemical not for consumption.

Teacher Notes

• When choosing the cereals, I would recommend using General Mills Total Cereal as the “healthy” option and either Post Cocoa Pebbles or General Mills Lucky Charms as the “kids” option.  These cereals will give you a big difference in the amount of iron that is collected.
• Depending on the intensity of the magnetic stirrer or magnet used, you may want to wrap it with aluminum foil reduce the stirrer’s ability to collect the iron filings.  Plastic wrap can also be used.
• Crushing the cereal with a mortar and pestle with speed up the separation process, however if you do not have a way to crush the cereal you can proceed without completing this step. In this case allow 15-20 minutes before removing the magnet from the mixture.

Cross-Disciplinary Extensions

Connect to Reading

• Have students research the history of cereal and how it came to be.  Who is credited with being the first cereal company and where is it located?  Is that company still in existence and producing cereal today?  If so, what are some of the cereals they are producing?  How different is the cereal of today when compared to the first cereal(s)?  Is cereal a world-wide breakfast food or is it primarily consumed in the US?

Connect to Social Studies

• What is the daily amount of iron recommended by the FDA?  What percentage of this recommended amount is given in the “kid” cereal?  What percentage is given in the “healthy” cereal?  What occurs if you do not ingest the daily recommended amount?  What occurs if you ingest more than the daily recommended amount?

Analysis

1. Calculate the amount of iron that was removed from the “kid” cereal:
2. Calculate the amount of iron that was removed from the “healthy” cereal:
3. Compare your answers to questions 1 & 2. Was there more iron in one of the cereals? Which one? Does this additional iron make the cereal better or worse for you to ingest?
4. Is there any correlation between the amount of iron in a “kid” cereal and the amount of iron in a “healthy” cereal? Research at least two types of “kid” cereal and two types of “healthy” cereal types to determine if your hypothesis is correct.
5. Many cereals are listed as being “fortified.” What does this mean? Give an example.
6. Is cereal the only food that contains iron? What other foods contain iron? Are there other metals that we ingest? If so, what are the other metals and what foods are they found in?
7. Determine the percent composition of the iron in each of the breakfast cereals. Pretend that there are only two ingredients in the cereal, iron and everything else. Use the formula below: