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Problem 3

BET analysis​

In this problem, you will determine how well the BET model describes our simple adsorbate system.

  1. Obtain isotherms up to P/P0P/P_0 at both T=0.90 and T=1.0 for ϵ=5.0\epsilon = 5.0 and ϵ=7.5\epsilon = 7.5, as in Example 1. How do they differ?

  2. Make "BET plots" of 1/[A(ads)](P0/P−1)1/[A(ads)](P_0/P - 1) vs P/P0P/P_0 (see [BET model](Adsorption/BET model) for details) for each of your data sets. Obtain values for CC and [S]0[S]_0 in each case, by fitting a line to data between 0.05 < P/P0P/P_0 0.30. (Make sure to have several measured points in this region of the isotherms!

  3. How similar are the values of the monolayer capacity obtained?

  4. The quantity CC should be proportional to eEa/kTe^{E_a/kT}. How well do your data fit this relation?