Up, up and away...
 

Introduction:

Blimps, balloons, and zeppelins all fly because they are lighter than air; they float in the atmosphere rather than sinking in it.  Airships are made of lightweight material and historically, they have have been filler with either one of two least dense elements: hydrogen or helium.

In this WebQuest, you are going to examine the chemistry behind "lighter-than-air" flight.  The history of airships involves some great chemistry but it also includes some really tragic chemical mistakes.  You will also use the gas laws and the relationship between temperature, volume and pressure to investigate why lighter-than-air objects perform the way they do.

The Participants:

You.  If you choose this project, you will be working by yourself.  If you wanted to work with someone else, choose the Gas Laws Scuba Project instead.

Your task:

You mission is to use the internet to explore and then explain answers to the questions below involving lighter-than-air flight.  You will create a PowerPoint presentation or a webpage which addresses each question or problem posed.  As you research, you will need to find websites that are most useful to you in answering the questions posed; you will reference your answers to the websites you use to explain your answer.  A part of the grade will be your careful consideration (i.e. validation) of the websites that you use to reference and support your answer. 

The process:

  1. There are three kinds of airships that have been manufactured: blimps, dirigibles, and hot air balloons.

• What is the mechanism of flight for each one?  That is, how does each fly?
• How are these airships similar?  How are they different?
• What are the relative advantages of one over the other?
• What are the limitations of each?
• Give historical examples of each and be sure to include at least one photo for each one.

  2. The German zeppelin Hindenburg was filled with hydrogen gas.  Not surprisingly, the airship was destroyed in a violent fire near Lakehurst, New Jersey on May 6, 1937.

• Write the balanced chemical equation for the combustion of hydrogen.
• We know that chemical reactions are often exothermic or endothermic.  What do these words mean in terms of chemical reactions?  What are observable chemical indicators of each?  Is the combustion of hydrogen exothermic or endothermic?

3. Modern airships are filled with helium. 

• Why are modern airships filled with helium? 
• Why wasn't the Hindenburg filled with helium instead of hydrogen? 
• Using a diagram of orbital diagrams or electron configurations or both, explain why helium is safer than hydrogen for use in airships.  Use diagrams and words to explain your answer.

H₂ 4. Though more potentially dangerous, a given volume of hydrogen gas will lift more weight than an equal volume of helium because hydrogen is less dense than helium.

• Use Avogadro's hypothesis to explain why hydrogen is less dense than helium.

  5. The Hindenburg was filled with flammable hydrogen but recent research suggests that hydrogen was not the primary material involved in its tragic demise.

• How did a paint made from powdered aluminum contribute to the disaster?
• How is powdered aluminum used on the current United States Space Shuttle?
• Write the balanced chemical equation for the reaction aluminum underwent in the Hindenburg disaster.  Also indicate if this reaction is exothermic or endothermic.
• Use the octet rule to explain why powdered aluminum can behave as it is thought to have done in the Hindenburg disaster.
• Do you think an aluminum can would behave in the same manner as powdered aluminum?  Explain your answer in detail.
• Describe the experiments carried out by Addison Bain.  Then, explain how his results and other evidence led to the conclusion that the skin of the Hindenburg was the major cause of fire that destroyed the airship.

6. Hot air balloons are filled with air instead of helium.

• How does the handler "pilot" his airship? That is, how does the pilot get the balloon to go up into the sky? How does the pilot get the balloon to descend to the ground?  Explain how the pilot travels north, south, east or west.  What kind of control do they have over this?
• Use the ideal gas law to explain why a hot air balloon rises.

7. French chemist, Joseph Gay-Lussac is most famous for his description of the gas law, Gay-Lussac's Law.

• What is the formula for Gay-Lussac's gas law?
• Explain Gay-Lussac's law using words to describe the relationship between the variables.  What are the assumed constants in Gay-Lussac's law?
• How did Gay-Lussac use balloons to study chemistry in the early 1800s?
• What did he learn from investigations he carried out using a hot air balloon?

8. It makes sense that a balloon filled with a lightweight gas such as helium would float when surrounded by heavier air. But why does filling a huge balloon with hot air also make it float? This resource from the NOVA website offers a series of interactive activities that describes and illustrates the chemistry (mass, volume, density) of what happens inside hot air balloons.

• Go through this NOVA site and then summarize the key points learned.

9. An airplane typically cruises at an altitude of 30,000 - 40,000 feet.

• Hypothesize what problems might be encountered in a suddenly depressurized airplane cabin at 30,000 feet.  Be sure to use what you have learned about the gas laws in answering this question.
• There are many myths regarding sudden depressurization.  What are some of the myths?
• What would actually happen if a window or emergency door came off of a plane cruising at 30,000 feet? Why?  Be sure to use what you have learned about the gas laws in answering.

The report:

You will turn in one of two options:  (Note - for Spring 2008 - students have the Word Document choice as well....)

• PowerPoint Presentation (Office 2000 or later).

  • Must contain a minimum of 25 slides.

  • Must include clip art, original art, color and/or graphics.

  • NOTE: In order for a movie to play within a Microsoft Power Point, the supported movie file formats are: .asf, .wma, .wmv, .wm

  • Movies that require QuickTime (Apple products) will NOT be fine and will NOT run within a Microsoft product (thank Bill Gates for that one....).

• Web page.

  • If you use your own server space, all you need to do is email us the fully qualified URL.

  • Must include clip art, original art, color and/or graphics.

For any of the options above ...

• NO spelling errors of any kind are allowed. 5% deduction (5 points out of 100) for  any spelling errors.  Grammar counts too!  Have someone proof your work!  Remember, in the "real world" of "final presentations," folks don't tolerate any grammar or spelling mistakes.

How do you give us your project? BY EMAIL - no other way is accepted.

• When you email us your project, you MUST include in the SUBJECT LINE the following (and in this order):
  Your block number and your name(s)    Example:   G3/Janelle Smith

• Send your projects to YOUR TEACHER:

  • Mr. Schulenborg   merleschulenborg@msdlt.k12.in.us

  • Mrs. Weir  janweir@msdlt.k12.in.us

The specifics:

1. Organization

• You must have a title page.  On it, be sure to have your name and your chemistry block and your teacher name.
• Each page must have the questions on the top of each page so it is clear to the reader what question you are answering.
• Your report or PowerPoint or website will be at least 20 pages since each question needs to be on a separate page.

2. References

• Each time you answer a question, you must cite (website address) your source at the bottom of the page. 
• Don't forget that just because you are including a reference, you must ALSO put the answers in your own words.  You want to make it very clear to the evaluator of this project that YOU wrote the answers and YOU understand the answers. 
• Copy/pasting information OTHER THAN images used or the reference site is forbidden (called plagiarism!)
• Any degree of plagiarism will result in ZERO CREDIT for this project.  Again, use the references but write in your own words.
• Remember, there are a myriad (lots!) of websites out there in cyberspace.  You must carefully CHOOSE the best website to reference - what you will do is "validate" your source by deciding if that particular website is the "best" one.  Remember, the first site that comes up in Google is not necessarily the "best" one!

3. Technology

• Your project must include graphics - graphics make reading visually interesting (that is, less boring!)
• Color is important.  Use it.

4. Due date:  See the schedule on ChemCentral. 

5. Grading rubric

Partial source:   http://www.chemheritage.org/Educational Services/webquest/blimp.htm