Chemical Forums
Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: flagpolesitta43 on April 26, 2006, 09:57:55 PM
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Find the equlilbrium constant at 25 C for the reaction
2NO2(g)---->N2O4(g)
the following data is also at 25 C:
NO2: ^enthalpy of formation: 33.8 kj/mol, ^gibbs free energy of formation: 51.8 kj/mol, entropy of formation is 240.4 J/mol-K
N2O4: ^enthalpy of formation: 9.7 kj/mol, ^gibbs free energy of formation: 98.3 kj/mol, entropy of formation is 304.3 kj/mol
Can I use ^G(standard)=-RTlnK? I'm not sure if K is equliibrium constant or Freedman's constant, and if I use that equation what value do I use for ^G? I know ^G is zero at equlilbrium, but I'm not sure if ^G(standard) is also zero at equlilbrium. Thank you for your help, I really appreciate it.
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Yes, (Delta)G = - RTlnK is the right equation to use. Here, K does stand for the equilibrium constant. (Delta)G(standard) is not zero at equilibrium; it's just the value you would calculate using the free energies of formation.
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Thank You very much you've been a big help :) :)