Eat Iron?!
Box panel from iron-fortified cereal box.Copyright 2005 U.S. Department of Agriculture http://www.ars.usda.gov/is/pr/2005/050512.htm
To gain an understanding of mixtures and the concept of separation of mixtures, students use strong magnets to find the element of iron in iron-fortified breakfast cereal flakes. Through this activity, they see how the iron component of this heterogeneous mixture (cereal) retains its properties and can thus be separated by physical means.
Mixtures are characterized by the fact that they can be separated into their components by physical means, such as filtration, evaporation, sublimation and magnetic separation. It is common and important in chemical and petroleum engineering to use a combination of such processes to separate mixtures into their distinct components. An example chemical separation application is the processing of crude oil, which is a mixture of various hydrocarbons. While valuable in this natural form, demand is far greater for various purified hydrocarbons, such as natural gases, gasoline, diesel, jet fuel, lubricating oils, asphalt, etc. Water purification is another example of the application of separation techniques. Separations methods take advantage of differences in chemical properties such as size, shape, mass or chemical affinity between the constituents of a mixture. The magnetic separation technique uses magnets to separate iron particles from a mixture.
After this activity, students should be able to:
- Distinguish and describe the three types of matter: elements, compounds, mixtures.
- Define pure and impure materials.
- Give some examples of elements, mixtures and compounds.
- Explain the different properties of each group of materials.
- Explain how engineers use the magnet separation technique to separate ferrous and nonferrous materials.