Main objectives:
Students will be able to describe the effects of acid rain on building materials.
Instructional input:
Acid rain degrades many types of materials that we use to build buildings and monuments, if they are exposed to it for long periods of time. Even though these materials would disintegrate with exposure to regular rainwater, acid rain speeds up this process. The damage that acid rain can cause to buildings costs billions of dollars to repair.
Materials:
Apron, gloves, goggles, acidic water solution (pH 3), 2 medicine cups, limestone chips, magnifying lens, pipet, pure distilled water (pH 7)
Procedure
:
Be sure to follow all safety precautions
1. Students should label the medicine cups #1 (pH 3) and #2 (pH 7) and place three limestone chips in each. They should examine their limestone chips and record their observations in data table E. If students wish, they may weight eh limestone chips on a triple beam balance or other scale.
2. Using a pipet students should and 2 ml of acid water solution to the cup labeled #1 and 2 ml of water to the cup labeled #2. After 15 minutes students should remove the rocks from the cups with tweezers and record their observations in the data table.
3. Students should replace the rocks into their respective cups and leave them overnight and take observations the next day.
Data Table E
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Observations
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Observations
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Time
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Cup #1 (pH 3)
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Cup #2 (pH 7)
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Start (prior to treatment)
15 minutes
24 hours
Students should write up a lab report according to the scientific method. They should include a statement of the problem, hypothesis, procedure (including dependent and independent variables and a control), data, conclusions and validity.
Students should also answer the following questions:
1. What changes did you observe in the limestone chips in both cups?
2. How can acid rain affect building materials?
Alternate activity Worksheet
The Effect of Acid Rain on Building Materials
When a chemical is applied to a sample of another chemical and bubbles are given off a chemical reaction is taking place. Acids can react chemically with some kinds of rocks. In this activity, you will find out whether acid (vinegar) reacts with various kinds of rocks.
Materials:
Strong vinegar, different types of rocks (marble, sandstone, granite and cement)
Procedure:
Adhere to all safety guidelines
Demonstrate the method for testing for reactions with acids. Apply 1 ml of strong vinegar to the rock sample and observe closely for bubbles or fizzing (look and listen)
Record the data in table F
Data Table F
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Observations
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Observations
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Observations
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Rock Type
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Visual Observations
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Sounds
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Other
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1. Sandstone
2. Marble
3. Granite
4. Concrete
5.
6.
Post lab activity
Answer the following questions:
1.How are the rocks that you tested used by people?
2.What implications do your observations have for builders?
3.Which building material that you tested seemed to be the most resistant to the vinegar?
4. In what ways is this activity a realistic simulation of the effects of acid rain and in what ways is it not realistic?