1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Gibb's free energy (very simple one)

  1. Mar 29, 2007 #1
    1. The problem statement, all variables and given/known data

    Calculate the equilibrium constant for the reaction forming nitric oxide at room temperature, 25C. G= 1.73x10^5 J/mol, H = 180.5KJ/mol an S = 24.8J/(mol.K)

    2. Relevant equations

    ln K = -G/RT

    3. The attempt at a solution

    I subsiuted ln K = (-1.73x10^5) / (8.3145x298.15)
    ln K = -69.78
    e^-69.78
    I'm getting K as 4.95*10^-31

    but the computer (where I submit online assignment ) is saying its wrong ... I've only one single attempt left ..can anyone see where I'm wrong.
    Thanks and immediate help please!
     
    Last edited: Mar 30, 2007
  2. jcsd
  3. Mar 30, 2007 #2

    chemisttree

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Please show some more work. In particular, how did you obtain the value for G? What units did you use for R and S? Example: H is in KJ/mol and S is in J/molK. When I mess up these calculations, it is usually related to units.

    BTW, for a very useful compilation of R in various units, consult the CRC Handbook of Chemistry and Physics. In the 84th edition (2003-2004), a very complete table is printed on page 1-54.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Gibb's free energy (very simple one)
  1. Gibbs Free energy (Replies: 3)

  2. Gibbs Free Energy help (Replies: 5)

  3. Gibbs Free energy (Replies: 1)

Loading...