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TROPOSPHERIC OZONEName: Tamara Grams

Teacher: Mrs Ramanaden

Due date: 16/05/14

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Research Question

Is there more tropospheric ozone in the center of Brisbane city compared

to the outskirts of the city?

BACKGROUND INFORMATION

Ozone is formed as ultraviolet radiation from the sun breaks down theoxygen in the atmosphere. Most tropospheric ozone is not produced

directly from human activity but is formed by the action of sunlight on

nitrogen oxides in the presence of a wide range of volatile organic

compounds (VOCs) emitted mainly by the combustion of fuels in motor

vehicles and industrial processes.

At ground level, ozone is a major component of photochemical smog

which has a visible light brown colour. This Smog has wide-ranging effects.

It can affect human health through eye, nose and throat irritations and in

short term can cause coughing, chest pain and other respiratory irritations.In long term, continuous exposure can damage lung tissue, contribute to

chronic lung disease and decrease life expectancy.

(http://www.sciencedaily.com/articles/t/tropospheric_ozone.htm)

The data will be recorded at 3 different sites from the center of Brisbane

city to Mt Cootha forest. The data will also be recorded each day for 3

days at exactly 5am to provide a fair test. High levels of ozone usually

occur after the sun has had time to react fully with the exhaust fumes from

the morning rush hour. These sites where choosen as each location is very

diverse from one another. Site 1 will be measured directly in the centre of

the city; this area contains more tropospheric ozone as of cars, exhaustfumes and other contributing factors. Site 3 is in Mt Cootha forest in which

no cars are present, this should produce low levels of tropospheric ozone.

While site 2 is a combination of both site 1 and 3. See Figure 1

Figure 1 Map of Brisbane to Mt Cootha

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Measuring concentration of tropospheric ozone; Schoenbein paper

Ozone measuring was first discovered by Christian Friedrich Schoenbein in

1839. Schoenbein paper is a chemically reactive paper, which is used to

measure the concentration of ground-level (tropospheric) ozone.

Schoenbein developed a way to measure ozone on the troposphere

using a mixture of starch, potassium, iodide and water, spread onto filterpaper.

Ozone in the air will oxidize with the potassium iodide on the test paper to

produce iodine. The iodine reacts with the starch to produce a purple

colour. The shade of purple on the exposed paper correlates with the

concentration of ozone present in the air at the test site. The darker the

color, the more ozone is present.

The following formula is the two chemical reactions which occur:

Hypothesis

The further away from the center of Brisbane city the less tropospheric

ozone there will be present.

Independent variable: Location/site in which the data is measured

Dependent variable: concentration of tropospheric ozone present

measured in Dobson units

Controlled variables

Location The data will be recorded in the

same location each day by using

a GPS

Time The data will be measured at 5am

each day for 3 days

Method By following the method there

should be consistent data

throughout the experiment

Record The data will be recorded on the

same raw data table at each

location

Weather/Climate The results will be measured at

exactly the same time every day

for 3 days in sequence to avoid

any significant weather changes

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METHOD

Schoenbein paper materials

- Safety goggles

-

Paper clip hangers

- 250mL beaker

- Hot plate

- Distilled water

- Potassium iodine

- Cornstarch

- Paper for drying filter paper

- Filter paper

- Small paint brush

- Glass stirring rod

-

Zip lock bags- Small paint brush

- holepuncher

- Scissors

- Hot pad or mit for removing the beaker from the heat source

Preparation procedure for testing solution

1. Place 100mL of distilled water into a 250mL beaker.

2. While stirring add in approximately 5g of cornstarch

3. Place the beaker onto hot plate. Heat the mixture, over low

heat, while stirring until the mixture is thick and translucent4. Remove the beaker from the hot plate and add in

approximately 1g of potassium iodide into the mixture and stir

well

5. Cool the solution

6. Lay filter paper on a piece of paper and use a small paintbrush

to apply the paste evenly onto both sides of the filter paper.

Apply the paste as uniformly as possible for immediate testing

paper is ready to use

7. Wash hands after applying the potassium iodide mixture

Storing the Schoenbein paper for later use

8. Dry the Schoenbein paper in a drying oven, at a low

temperature out of direct sunlight.

9. Punch a hole using the holepuncher into schoenbein paper in

order to hang

10.Place the stripes in an airtight ziplock bag and keep out of direct

sunlight.

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RECORDING DATA

Materials for collecting field data

- GPS

-

Recording materials

- Schoenbein Paper

-

Distilled water-

Timing device e.g watch and/or stopwatch

- String

- Scissors

Method

Three different researchers will measure the data at different sites, each

day over a period of 3 days.

Researcher 1

1.

Using the GPS Start at site 1 coordinates

(-27.469551,153.026053)see map 1

2. Measure Ozone using Schoenbein testing paper

3. If Schoenbein strips have been freshly made, they are ready for

immediate use. If strips have been stored, moisten a strip of

Schoenbein paper with distilled water

4.

Hang strip out of direct sunlight using string the strip must hang

freely

5. Expose the 5 strips at exactly 5am for 8 hours.

6. Remove the strips and place into an airtight ziplock bag

immediately out of direct sunlight until results are recorded.

7.

Repeat steps 1

5 for 3 days

Researcher 2

8. Using the GPS go to site 2 coordinates (-27.475491,152.987086) see

map 1

9.

Repeat steps 2 6 for 3 days

Researcher 3

10.Using the GPS go to site 3 coordinates (-27.472902,152.949835) see

map 1

11.

Repeat steps 2 6 for 3 days

12.To observe and record test results (record all results on raw data

table), spray the paper with distilled water, observe the colour using

the Schoenbein/humidity chart as follows

a. Along the bottom of the chart, find the point that corresponds to

the Schoenbein number

b. Draw a line upward from the Schoenbein number until it

intersects the curve that represents the correct relative humidity

c. Draw a line from the intersection in (b) to the left side of the

chart. Note your ozone concentration

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Figure 2 Schoenbein Colour Scale

Raw data table

Strip 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5

SITE 1 Schoenbein

number

Relative

humidity on

testing day (%)

SITE 2 Schoenbein

number

Relative

humidity ontesting day (%)

SITE 3 Schoenbein

number

Relative

humidity on

testing day (%)