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Atlantic Bilingual
School

Students: Alberto Lopez
Alex Hilsaca
Anthony Clarke
Pablo Lozano

Topic: The Science of Making Perfume

Teacher: Christian Campbell


Delivery Date
06/02/10

Got Iron? Use a Color-based Test to Measure the Concentration of Iron in Water
Did you know that your body needs a certain amountof iron in order to stay healthy? Iron is an essential part of the hemoglobin complex in your blood, which carries oxygen from your lungs to the rest of your body. It is also involved in many other biochemical processes in your body. Iron can be found in much of what you consume each day. In this chemistry science fair project, you will use a simple test kit that produces an orange-coloredchemical in the presence of iron in a solution. The kit will be used to measure the rate at which solid iron (from steel wool) is dissolved into the solution. The test can then be used to measure iron in your drinking water and in iron-fortified foods.ObjectiveUse a color-based chemical test to measure the rate at which solid iron dissolves.IntroductionIron is essential to most forms of life and tohealthy human physiology. It is a key part of many proteins andenzymes that help you maintain good health. In humans, iron is an essential part of proteins that are involved in oxygen transport. Almost 66 percent of the iron in your body is found in hemoglobin, which is the protein in red blood cells that carries oxygen to tissues. Smaller amounts of iron are found in myoglobin, a protein that helpssupply oxygen to muscle. A deficiency of iron limits oxygen delivery to cells, resulting in fatigue, poor work performance, and decreased immunity. On the other hand, excess amounts of iron can result in toxicity, and even death.Even though iron is the second most abundant metal in Earth's crust, iron deficiency is the world's most common cause of anemia. As far as your body is concerned, iron ismore precious than gold. The body stores iron so effectively that there is no biological process for the excretion of iron. The amount of iron in your body is regulated by how much iron is absorbed from food by your intestines. The recommended daily allowance (RDA) for iron depends on your age and gender. According to the Office of Dietary Supplements-National Institutes of Health, for peoplebetween the ages of 14 and 18, the minimum daily requirement is 11 milligrams (mg)/day for males and 15 mg/day for females.Scientists have developed various chemical tests for determining the amount of iron in a substance. For this chemistry science fair project, you will use a colorimetric test for iron. The chemical test is based on anindicator molecule called 1,10-phenanthroline. 1,10-phenanthrolineproduces a clear solution when no iron is present, but produces an orange-red color in the presence of iron. The greater the concentration of iron in asolution, the more the solution will turn orange-red (in other words, the color change is proportional to the iron concentration). The test is designed to detect all soluble forms of iron (iron that is dissolved in the solution) andmost insoluble forms of iron (iron that is still in solid form). In the presence of iron, phenanthroline molecules combine with iron atoms to form an orange-red complex. The structure of the phenanthroline-iron complex is shown in Figure 1, below. |
Figure 1. Structure of phenanthroline molecule complexed with iron. Note that there are three phenanthroline molecules for every iron atom in a phenanthroline-ironcomplex. (Wikipedia, 2009.) |
In this chemistry science fair project, you will use the colorimetric test to measure the rate at which solid iron is dissolved in an indicator solution. As the iron dissolves, it reacts with phenanthroline in the solution to form the orange-red complex. The rate will be measured as the increase in the concentration of iron (as determined by the color) divided by...