Chemistry in Foods
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Viva Henson Andrew Jackson
1340 W. Harrison
Chicago, IL 60609
To develop an understanding of the function of indicators.
To develop an understanding of some simple chemistry concepts.
To identify acids and bases in foods.
To develop skills recording information and keeping charts.
For each group of 4 or 5 students:
cabbage indicator paper
blackberry indicator paper
onion indicator paper
aluminum foil or small aluminum, styrofoam or plastic trays
various juices and foods--such as: corn, apple juice, pickle juice,
orange juice, rhubarb, potato water, rice water and baking soda
plastic cup of water
1. This activity will be done after the teacher has discussed indicators, acids
and bases and has tested several household products by using litmus paper.
2. This activity will be done with the entire class in groups of four or five.
3. Each group should have at their stations a few strips of each of the
indicators, samples of all of the food items, a plastic cup of water and
aluminum foil, styrofoam, aluminum or a plastic tray on which they will lay
their indicators after they have been dipped into each of the juices and
4. After each food has been tested, the students are to record their findings.
Blackberry Indicators -- turn blue when dipped in a base and red when
dipped in an acid
Onion Indicators -- turn green when dipped in a base and colorless
when dipped in an acid
Red Cabbage Indicators-- turn green when dipped in a base and red when
dipped in an acid
Students will understand that there are two classes of chemicals which can
be indicated by using colored indicator paper. Students will also discover that
in order to test for acids and bases the food must be wet or in liquid form.
Through discovery, students will pour water into the baking soda to get a
reading using the indicators. Students will understand that there are chemical
compounds in foods and there seems to be a higher number of foods with acids