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Homework Help: Chem. experiment

  1. Feb 14, 2010 #1
    hey i need help with this 1 i did the experiment but this last problem is killing me

    Analysis
    Hint: As you are thinking about this we want you to know that the water in the can and in the pan is only there to heat or cool the air in the can. In 5.07 you studied the relationships of temperature and pressure as it affects volume. Use this knowledge in explaining your results. Also, don't forget about atmospheric pressure!
    Before you begin the analysis think about what was actually happening to the gases inside versus outside the can. Think in terms of where the pressure is greatest, versus less.
    1. What happened when you put the can in the water?
    The can imploded and made a “popping” noise.


    2. Why did this happen?
    This happened because when the temperature in the can decreased, the volume in the can decreased as well. This made the pressure inside the can decrease. The result was the pressure inside the can was lower than the pressure outside of it. The atmospheric pressure made the can implode and pushed the sides of the can together.


    3. Why did you have to turn the can upside down?
    I think the can was turned upside down so that air would not get into the can really fast. This prevents it from increasing the decrease in the air volume inside the can.


    4. What gas law would account for what happened?
    The law that would account for what happened would be Boyle's Law.


    5. Explain how your choice of this gas law is supported by your observations.



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  2. jcsd
  3. Feb 14, 2010 #2

    ideasrule

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    Homework Helper

    The pressure of WHAT? The volume of WHAT? You have the right idea, however.
    This is very confusing.

    Kind of, but Boyle's law only gives the relationship between pressure and volume. It doesn't say that pressure decreases when temperature does for constant volume or volume decreases when temperature does for constant pressure.
     
  4. Feb 15, 2010 #3

    Borek

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    Staff: Mentor

    You have not described the experiment, so we have to guess parts of it, but

    What happens to the hot air?

    --
    methods
     
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