How many colors does iron have?

Iron and the oxidation-reduction process: Iron is a common element of many creeks, especially in the Appalachian region. Iron (Fe) has many different forms and many different colors. Each color tells a different story about the chemistry of the creek. Iron that is naturally found in the creek normally does not cause problems (it is part of the soil and the sediments), but metals can be increased by human activities to a point where they may become harmful to life in a creek. With iron, red is oxidized and black is reduced.

Tools and things you will need

• Eyedropper
• Gloves
• Jars with lids
• Litmus paper
• Magic markers
• Rubber boots
• Shovel

1. Fill jars with red, yellow, or orange flocculates (flakes that occur in the water, on rocks or on the bottom sediments) and water from a creek. These can be found in many creek, but are especially common in creeks affected by acid mine drainage.
2. Dig with a shovel in different places in and along the creek bed, until you find the color change from red to black.
3. Add some black sediment to some of the jars (and make sure water is to the top to keep out oxygen).
4. Label the jars with the dates of collection.
5. Put covered jars on a north-facing windowsill and observe them over several weeks.

What did you see?

1. Make observations as to what happened to the colors over several weeks.
2. At the end of the experiment, uncover the jars and smell them. "Write down what you smell."
3. What else did you see?

What did you conclude?

1. Which of these colors are from iron?
2. Which iron was oxidized and which was reduced?
3. What are your conclusions? "Write down what you think."