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Homework Help: Air problem

  1. Nov 27, 2007 #1
    1. The problem statement, all variables and given/known data
    Air is a mixture of 78% nitrogen, 21% oxygen, 0.09% of argon, and 0.03% of carbon dioxide. What can be said about air?

    a) Air is a heterogenous mixture
    b) Air is a pure substance, and is made up of N, O, Ar, and C
    c) Air is a solution, in which nitrogen is the solvent
    d) Air is a solution, in which nitrogen is the solute

    2. Relevant equations
    None


    3. The attempt at a solution
    I put c). Am I right?
     
  2. jcsd
  3. Nov 27, 2007 #2

    Gokul43201

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    Yes. Do you understand why this is correct?
     
  4. Nov 27, 2007 #3
    I got the answer mostly because I thought that the other choices were not correct answers. Also, since nitrogen makes up most of our air, I thought that it would be the solvent. If my reasoning is not going in the right direction, could you help me please?
     
  5. Nov 28, 2007 #4

    Gokul43201

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    That's essentially correct.

    A heterogeneous mixture must have more than one phase - not the case with air as described in the question (though real air is filled with all manner of solid particulates). Air is not a compound - it can be separated into its constituent gases by "physical" means, and its composition is definitely not fixed.
     
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