Download Experiment Design: Acid Rain

Honors Biology
Experimental Design
Design an experiment for each of the following problems.
Example 1: Acid Rain
Before falling to Earth as precipitation, water vapor in the atmosphere normally reacts with carbon dioxide gas
to form a weak acid, carbonic acid (H2CO3). As a result, the pH of rainwater is approximately 5.6, making
typical rainwater slightly acidic (neutral ph being 7). However, water vapor in the atmosphere will also react in
a similar fashion with other gases, including sulfur dioxide (SO2), nitrogen dioxide (NO2), and nitrogen trioxide
(NO3). These gases are pollutants that result from the burning of fossil fuels: for example, in car exhaust and
factory emissions. These reactions will produce acids stronger than carbonic acid, including sulfuric acid
(H2SO4), nitric acid (HNO3), and sulfurous acid (H2SO3). If the concentration of these acids in the atmosphere is
high enough, the pH of rainwater can be lowered considerably. Rain with a pH lower than 5.6 is considered
"acid rain" and can have significant environmental effects on natural ecosystems and on buildings, statues, and
other structures.
On a separate sheet of paper
1. Design an experiment that would simulate outdoor conditions of acid rain damaging an object of your
choice. Vinegar can be used to simulate acid rain.
Include and identify the following:
- hypothesis
- control group
- experimental group
- independent variable
- dependant variable
- controlled variables
2. Design a procedure.
- make sure that you use numbered steps (like a cook book)
- be very specific
3. Make a fictitious data set and do the following:
- make a table of your fake data
4. Make either a scatter plot or line graph from your table.
- be sure to include all labels and keys
Example 2: Be Still My Beating Heart
A person’s heart rate depends on a variety of factors, including overall health, age, level of activity, and
altitude, to name a few. In general, a higher level of activity or exertion tends to increase heart rate, which
returns to normal after a recovery period following exercise. Individuals who are in better physical shape have
heart rates that are lower during rest and recover much more quickly after physical exertion than those in poor
condition. Design an experiment to test this hypothesis.
On a separate sheet of paper perform the same task as above.