1. Apparatus 1. Potassium Iodide 2. Cornstarch 3. A 50 mL Beaker 4. Plastic Pipette 5. Clean Empty Test Tube

2. 6. Distilled Water 7. Scissors (or paper cutter) 8. Ruler 9. Pencil 10. Typing paper

3. Place dots at one centimeter intervals on a paper. This is the width we will make the strips. Measure out 10 dots (10 centimeters) for 10 strips.

5. Measure 12 centimeters from the bottom of the sheet and draw a line across the paper. Again, mark along that line at one centimeter intervals.

7. These drawing lines are guides for cutting out the strips.

10. Place 100 ml of distilled water into a 250 ml beaker. Stir in 5 g of cornstarch.

11. Place the beaker on a hotplate over lowheat and stir till the contents are transparent.

12. Remove from the hotplate and stir in 1g of potassium iodide. Cool the solution.

13. Dip your paper strips into the solution. Allow the strip to stay in solution for about five seconds before removing.

14. Lay the wet strip on a piece of paper, paper towel, or cloth. Let it dry.

15. Let them dry, which shouldn't take long, maybe 20 minutes. To preserve them, place them in a ziploc bag.

16. At this point where all the strips have been dipped, take a picture of them.

17. Testing for ozone at home and where you travel, and at school.

18. Place one strip outside where you live. It is best to place it outside in the morning and retrieve it 8 hours later. Anchor it down somehow. You can use a rock, but don’t cover up the part of the strip that had been dipped. Air needs to get to the strip. You can use tape, a paper clip or thumb tack if you want to secure it. But again, place it so air can get to it.

19. Take a picture of where you placed it.

20. Make a note of what time you placed the strip outside. You will need to leave it there for about 8 hours. You will also need to know the humidity. Use the web to know the humidity..

21. Place another ozone test strip inside your house somewhere. Again, it needs to be where the air can flow over it. Also, note what time you placed it. Retrieve it about eight hours later to read the ozone level.

22. Place a strip under the wiper blade of a staff car parked in the school parking lot. Remember to get the permission of the owner.

23. After leaving the strips exposed to the air for 8 hours, compare their color to the chart at the left (or the one below), and determine the "Schonbein number." Schonbein is the discoverer of ozone and gave it its name, meaning "odd smell". He also developed the test for ozone using the ingredients you are using in this lab.

24. The above color chart uses colors that are given in the literature, but the strips made with this kit seem to be closer to the color chart to the left. Use whichever one is easier to match.

26. Locate the Schonbein number on the bottom axis of the graph. In my case, the Schonbein number was 6.5. Come straight up and find the spot that comes the closest to the average humidity during the time you did the test. The average humidity was 32% for me, so it sits between the 30% and 40% lines, but closer to the 30% line. At that point go straight to the left to read the ozone concentration in parts per billion (ppb). The other reading of "1" is done the same way.

28. Below are the instructions of how to find the average humidity for the time the strip was exposed. First go to this site: http://weather.newsday.com/ 1) At the bottom left of the page, type in your zipcode. 2) A page will pop up with the current weather for that zipcode. Scroll down to the bottom of that screen.

29. 3) At the bottom of that page is a way to jump to a specific date with detailed weather information..

30. 4) After clicking the "Go" button, a page will come up with detailed weather information. Scroll down and find the table that has the humidity readings for that day. Find the time closest to the time that you placed the ozone strip outdoors and note the humidity for that time. Let's say you placed it out at 10am. Pick the 9:50am time and note the 22% humidity reading.

31. Now let's say you retrieved the strip 8 hours later at 6pm, so you would pick the 6:51pm time and note the 31% humidity. The average humidity is (22+31)/2 or 26.5% Use the 26.5% to adjust the Schonbein number to find the ozone ppb reading on the above graph

32. his is the table shown at the EPA website for air quality called, "AirNow". Their website is: http://www.epa.gov/airnow/ The reading above of 165 is in the unhealthy range. The reading of 40 is in the good range. http://www.epa.gov/airnow/

33. Report the following findings: Average Schonbein number for Inside strip=? Relative humidity (use outside)= ? Ozone ppb (Inside) = ?

34. Average Schonbein number for Outside strip=? Average relative humidity = ? Ozone ppb (Outside) = ?

35. Average Schonbein number for strip taken away from the home=? Average relative humidity = ? Ozone ppb (Outside away from home) = ? Location where this strip spent most of the day=? Send pictures that were taken.