Acid Rain And How It Affects Our Environment

Iftner, George              Schools, various
                      

Objective

Demonstrate phenomenologically the effects of acid rain on our 
environment and perform long-term "real-time" experiments.

Materials

6 Petri dishes, pipette, large bell jar or similar item, sulfuric 
acid, two 2-liter soft drink containers, 4 small pieces of marble or 
limestone, continuous strip of chart paper approximately 3 ft by 6 ft, 
pastel crayons or markers, small growing plant, 4 small pieces of raw 
fish, 2 green leaves, small amount of soil. 

Strategies

1.  2 or 3 days in advance, prepare Petri dishes with soil & stone, 
leaf, and raw fish.  One set is to be watered with distilled water, the 
other wetted thoroughly with 50% sulfuric acid.  Keep hidden from 
view.

2.  Prior to the lesson, a) cover an area of chalkboard or wall with the 
drawing paper; print OUR ENVIRONMENT at the upper right.  b) set out the 
Petri dishes prepared in #1 above, but keep covered from view for the 
moment.  c) make 14 slips of paper, each with one of the following 
printed on it:
  LAKE     FISH     CARS     FACTORY     WIND     SUN    FISHERMAN
  PEOPLE   SMOKE    TREES    RAINCLOUD   RIVER    HILLS  HOUSES

3.Pass out the name slips to 14 students at random.  Ask the class if 
they like to draw. (The response should be most positive - I've yet to 
see a class at any grade level that didn't like "artwork!")  Say 
something like  "Let's make a mural about our environment.  This 
should be fun!"  Have the slip recipients come up and draw that which 
is on their slip.  Be complimentary and encourage creativity!  Guide 
each artist as to the approximate location of his/her item...(the 
factory, cars, sun and smoke should be toward the left end of the 
production and the other items oriented toward the right.)

4.  Admire the production!  THEN, complete the title by adding "ACID 
RAIN AND HOW IT AFFECTS", so that the complete title now reads.
 
             "ACID RAIN AND HOW IT AFFECTS OUR ENVIRONMENT"

5.  Display the Petrie dishes and show the class how the acid has 
affected soil/stone, plant, and animal materials compared to the items 
in plain water.  Discuss briefly, then augment the mural with more smoke, 
rain, and wind, and describe how acid rain is formed. (Tailor the 
scientific descriptive language to the grade level involved, i.e., 
don't get involved with chemical formulas unless the class has had 
some exposure to them.)

6.  Create 3 or 4 groups and have the groups spend about 5 minutes 
listing what effects they think acid rain would have on the various 
aspects of their mural.  Poll the groups for their ideas and develop a 
list on a chalkboard.  Augment the list with any facets the class may 
not have considered.  Be sure to list all ideas even though not 
specific to acid rain...indicate that these items "fit better" in 
different topics and will be covered in future lessons.
 
7.  Set up the following long-term experiment:   
    a - Place the potted plant under the bell jar;
        Add a Petri dish or other small vessel of 10% sulfuric acid;
        (Maintain plant normally including acid solution).
    b - Put about one inch of 10-15% sulfuric acid solution into one of the 
        soft drink containers.  Suspend a marble or limestone chip 
        above the solution.  Cap tightly.
    c - Duplicate (a) and (b) with water only as controls. 
    d - Put a piece of raw fish in each of two Petri dishes; immerse 
        one in water and cover, immerse the other in weak acid 
        solution and cover.  (Note: these pieces of fish will 
        deteriorate but the effect of the acid solution will become 
        evident over a period of time.)

8.  Secure articles dealing with acid rain as available and distribute 
    to the class for their further interest and edification.

                         NOTE: SAVE THE MURAL!