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Is my calculation ok? - clausius clapeyron eq.

  1. Oct 10, 2009 #1
    I would like to calculate isosteric heat of adsorption (H). I have a series of adsorption isotherms for different temperatures and it appears that the adsorption increases with increasing temperature. This suggests that the process is endothermic. Using Clausius Clapeyron law, the slope of 1/T vs lnC gave me a number of positive value, about 1000, which results in negative H (slope=-H/R), about -8 KJ/mol. I suppose that something is not correct in my calculation as the process should be endothermic. Should not be the deltaH positive? Also, I have applied known equilibrium constant of adsorption to calculate deltaG which is negative , about -7Kj/mol, but decreases with increasing temperature.This would suggest that the adsorption is more favourable at higher temperatures. Do this two conclusions go together well? I am a bit confused.
    Last edited: Oct 10, 2009
  2. jcsd
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