Epidemic - The Deadly Fuchsia Disease
Materials
1 test tube or small plastic cup for each student for each part of the activity
1 clean dropper for each student
0.1M NaOH
0.1M HCL, vinegar, or other weak acid
1% phenolphthalein
Chemical Information
1. 1% Phenolphthalein solution can be purchased from scientific supply houses such as Ward’s Natural Science. http://wardsci.com/product.asp?pn=9465302
2. Sodium hydroxide solution, 0.1M
Place 4g NaOH pellets in a 1 L flask and slowly add 50mL distilled water with constant swirling until dissolved. Avoid creating and breathing dust. Then add enough distilled water to bring the total to 1000mL.
Disposal: Place 250mL in a 1 L beaker. Slowly add 0.5M sodium bisulfate until neutrality is confirmed by litmus test. Place beaker in a sink and run water to overflowing for 10 minutes.
3. Hydrochloric Acid, 0.1 M
Slowly add 8 mL concentrated HCL to 500 mL distilled water in a volumetric flask and fill to the 100mL mark.
Disposal: Neutralize only small amount (< 250mL) at one time. Slowly add 1M sodium bicarbonate until neutrality is confirmed by litmus test. Place beaker in a sink and run water to overflowing for 10 minutes.
Additional safety precautions during the preparation and disposal of NaOH and HCL
· Use face shield over goggles
· Use rubber nitrite gloves
· Use fume hood
· Ensure eyewash station nearby
· Ensure safety shower in close proximity to dispensing activities
· Label both containers of NaOh and HCl: CAUTION: Irritant
· Use NaOH and HCl only with close teacher monitoring
First aid: Eye/skin contact: Immediately flush with large amounts of water for 15 minutes, including under eyelids, Contact physician if irritation persists.
Ingestion: DO NOT INDUCE VOMITING. If patient is conscious, give large amounts of water followed by dilute vinegar or fruit juice. Contact physician.
Student Handout: Epidemic-The Deadly Fuchsia Disease
Section 1
Safety: Wear your safety goggles
Procedure
1. How does a disease spread? In this activity you will see how a disease spreads through a community over several days. Each “Day” will last about 5 minutes.
Your teacher will give you each a container of a clear liquid and a dropper. One student in your class has been infected with the Deadly Fuchsia Disease. This student has just arrived from part of the world where Fuchsia Disease is endemic (widespread). On “Day” 1 the student who is infected will infect two other students by putting a full dropper of his or her clear liquid into their containers.
What happened to the liquid in the infected students’ containers?
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2. For “Day” 1 record the number of newly infected students and the total infected in your data table.
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3. The next day the two newly infected students each infect two more students by giving them a full dropper of their liquid. Record the number of newly infected students and the total infected in your data table. |
4. Repeat step 3 until the whole class is infected. NOTE: only newly infected students can infect additional students. Assume that previously infected students are quarantined and thus unable to continue infecting more students.
5. This disease causes an individual to be ill for five days. After five days, they either recover or die.
6. Graph the number of infected individuals per day (use the data in the Total Infected column). Write a sentence or two that summarizes what happened.
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Day |
Newly Infected |
Total Infected |
Recovered or died |
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Day 2 |
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Day 3 |
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Day 4 |
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Day 5 |
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Day 6 |
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Day 7 |
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Day 8 |
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Day 9 |
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Day 10 |
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Section 2
Safety: Wear your safety goggles
Procedure
1. How can an epidemic be stopped?
2. In Part II of this activity you will see how a disease can be contained or stopped by vaccinating a percentage of the population. You may or may not be vaccinated for the Deadly Fuchsia Disease. You will know if you are vaccinated only after you are exposed to the infection.
Your teacher will give you another container of clear liquid and a dropper. Your teacher will decide which student in your class has been infected with the Deadly Fuchsia Disease. The student who is infected will infect two other students by putting a full dropper of his or her clear liquid into their containers. What happened to the liquid in the infected students’ container?
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If a change in a student’s container is observed, the student is infected and can infect others the next “day”. If no change is observed, the student was vaccinated and is not infected. Vaccinated students do not share liquid with other students.
3. Record the number of newly infected students and total infected students in your data table.
4. Every “day” each of the newly infected students (if there are any) infects two more students by giving them a full dropper of his or her liquid.
5. Repeat step 4 until no new student is infected in any one day. At that point the disease is contained.
6. This disease causes an individual to be ill for five days. After five days, they either recover or die.
7. Graph the number of infected individuals per day (use the data in the Total Infected column). Write a sentence or two that summarizes what happened.
8. ____________________________________________________________________________________________________________________________________________________________________________
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Day |
Newly Infected |
Total Infected |
Recovered or died |
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Day 1 |
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Day 2 |
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Day 3 |
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Day 4 |
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Day 5 |
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Day 6 |
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Day 7 |
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Day 8 |
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Day 9 |
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Day 10 |
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Follow-Up:
Answer the following questions:
1. Summarize what happens in your first graph:
a. Describe the graph
b. Explain what is happening in relation to the disease
2. Repeat question #1 for the second graph.
a.
b.
3. Compare your two graphs:
a. How are they different and/or the same?
b. Why are they different?
4. What would happen to the class epidemic if on any particular day only students who were vaccinated received fluid from infected students?
5. After doing this lab activity would you choose to have your children vaccinated against diseases? Why or why not?