Name __________________________________________________________________
Date __________________________________
Period _________________________________
Acid Rain Affecting Seed Germination
Background: Acid rain is formed by nitrogen and sulfur compounds combining with water molecules in the
atmosphere. The burning of fossil fuels causes these compounds to be released. When water vapor and
nitrogen or sulfur combines, it creates nitric acid or sulfuric acid. When these acids precipitate, they do so in
the form of acid rain. Acid rain can be potentially damaging to crops, forests and buildings. In this lab, you will
perform an experiment to test the effects of acid rain on seed germination.
Problem: How does acid rain affect the germination of seeds?
Materials:
9 radish seeds
pH paper
3 plastic sandwich bags
3 paper towels
100mL beaker
Erlenmeyer flask with vinegar
Eye dropper
Hypothesis: How do you think the radish seeds placed in a pH of 5 and pure vinegar will germinate
compared to radish seeds placed in neutral water?
Procedure:
Control Group
1.
2.
3.
4.
5.
6.
7.
Put 50 mL of water into beaker.
Thoroughly wet 1 paper towel with the water from the beaker.
Fold the wet paper towel in fourths.
Place 3 radish seeds inside wet paper towel. Spread seeds evenly inside the wet paper towel.
Label each seed 1, 2 and 3. Write directly on the paper towel.
Carefully place the wet paper towel with the seeds inside one plastic sandwich bag.
Label the outside of the second plastic bag with names, the period and control group.
pH 5 Group
1. Put 50 mL of water into beaker.
2. Pour small amounts of vinegar into the water beaker until a pH of 5 is reached.
3. Continuously test the pH of the solution by using an eye dropper. Place one drop of solution on a small
section of pH paper. Follow the directions for matching up the color of the pH paper.
4. Once a pH of 5 has been reached, follow steps 2-6 from the control group procedure.
5. Label the outside of the plastic bag with names, the period and pH 5 Group.
Vinegar Group
1. Follow directions from the pH 5 group, except continue adding vinegar to the water beaker until the
pH has reached 3.
2. Label the outside of the third plastic bag with names, period and Vinegar Group.
3. Staple all three bags together at the top of the bags. DO NOT PUNCTURE THE BAG.
4. Place your group’s bag in the designated area for your period.
Data
Growth of Seedlings (mm)
Day
Control
1
2
3
pH 5
1
2
3
Vinegar
1
2
3
1
2
Average
Growth
Questions:
1. What percentage of your control seeds germinated? pH 5 group? Vinegar?
2. Was there a difference in growth between the control and experimental groups?
3. Would you expect acid rain to affect plants that have already germinated? Justify your answer.
4. What do your results imply about the short term effects of acid rain? Would you expect there to be
long term effects? Why or why not?
5. Why did this experiment include a control group?
6. If you were to conduct this experiment again, what would you do differently? Explain why. (“Nothing”
is not an acceptable answer.)