Can artificial be beneficial? Consumers often associate food additives as being unhealthy and strictly used for convenience foods. This four-part demonstration lets students see the science behind some of the marketing.
- Extract iron from common breakfast cereal. Determine the form of iron present, and compare the quantity present to the quantity specified on the Nutrition Facts label. It’s elemental!
- Iodide is added to iodized salt to prevent thyroid and other diseases. Demonstrate the presence of this essential nutrient by oxidizing the iodide and doing a starch–iodine test.
- Do some simple measurements to illustrate how it’s possible to claim that salt substitutes have less sodium than regular table salt.
- Reveal the nature of the “secret ingredient” added to freshly cut fruit to prevent it from turning brown.
This great series of demonstrations will build connections between science and real life. Teacher Demonstration Notes included. Concepts:
Consumer chemistry, food additives. Time Required:
One full class period with follow-up the next day. Chemicals Provided:
Acetone, ascorbic acid, hydrochloric acid, iodized table salt, iron(II) sulfate solution, 1,10-phenanthroline solution, potassium iodide, salt sense, sodium chloride, sodium hypochlorite solution, starch solution.
Materials Included in Kit:
Acetone, 250 mL, 2
L-ascorbic acid, 15 g
Hydrochloric acid solution, 0.1 M, 75 mL
Hydrochloric acid solution, 1 M, 125 mL
Iodized salt, 100 g
Iron(II) sulfate solution acidified, 25 mL
1, 10-Phenanthroline solution, 10 mL
Potassium iodide, 10 g
Salt sense, 30 g
Sodium chloride, 40 g
Sodium hypochlorite solution, 80 mL
Starch solution, 30 mL, 0.5%
Foil barrier bag, 4½" x 3" x 12" x 4.3 mil nylon
Pipet, Beral-pipet, graduated, 14
Correlation to Next Generation Science Standards (NGSS)†
Science & Engineering Practices
Analyzing and interpreting data
Using mathematics and computational thinking
Constructing explanations and designing solutions
Disciplinary Core Ideas
MS-PS1.A: Structure and Properties of Matter
MS-PS1.B: Chemical Reactions
HS-PS1.A: Structure and Properties of Matter
HS-PS1.B: Chemical Reactions
Scale, proportion, and quantity
MS-PS1-2. Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.