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Homework Help: The proportion of Hydrogen to limit errors in measurement.

  1. May 14, 2013 #1
    It is proposed to use a katharometer to mesaure the amount (about 5%) of oxygen in nitrogen, in the presence of a small amount (0.5%) hydrogen. How constant would the proportion of hydrogen have to be in order to limit errors in measurement of % oxygen to +/- 0.1%?

    The thermal conductivities are:
    Nitrogen 0.993
    Oxygen 1.052
    Hydrogen 6.993

    Not to sure where to start with this one, any guidance just to start me off would be most appreciated.
  2. jcsd
  3. May 15, 2013 #2


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    An approximation of the mixture's thermal conductivity can be expressed as the mole fraction-weighted sum of the individual components. For example,

    λm = χ1λ1 + χ2λ2 +… χnλn
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