Experimental Design
Overall Experimental Task:
1. To design a pH test kit to test the acidity of soil.
2. To nurture a small hydrangea bush over a period of time to bloom
a specific flower color.
Part 1 (your known):
Your lab group will be given a hydrangea bush. Your task is to collect
data on factors that influence the color of the flowers on a hydrangea
bush.
Procedure:
1) You will be given either a hydrangea bush or hydrangea seeds.
2) You will then provide the necessary conditions to grow a healthy
hydrangea. Recall this information from your research.
3) Design a pH test kit by selecting an appropriate indicator and creating
a color chart for the indicator.
4) With your newly designed pH test kit, measure the initial pH value
of the soil.
5) If the pH is acidic, gradually raise the pH of the soil for 1 week.
How would you do this? If the pH is alkaline, gradually lower the pH
of the soil for 1 week. How would you do this? Record any observations
on a data sheet.
6) Repeat steps 4-5 until you have reached either the highest or lowest
pH condition for you hydrangea plant to grow. For instance, if you were
raising the pH, you would stop once the pH reached 6.4. If you were
lowering the pH, you would stop once the pH reached 5.0.
7) Once you have reach one extreme pH condition, repeats steps 4 through
6 until you have reached the other extreme pH condition. You should
have two sets of data: one raising the pH; one lowering the pH.
8) Analyze the data you have collected. On average, how much does the
pH increase with X grams of gardening limestone? On average, how much
does the pH decrease with X grams of gardening aluminum sulfate? How
much limestone would you need to add to raise the pH by 1.0? How much
aluminum sulfate would you need to add to lower the pH by 1.0?
Question:
Based on the data you collected and the information you learned from
your hydrangea research, how would you nurture a hydrangea bush to bloom
into a bold pink color if the original pH of the soil was 5.2?
To
Debriefing
