April 20, 2024, 03:38:21 AM
Forum Rules: Read This Before Posting


Topic: Work done by a voltaic cell  (Read 4532 times)

0 Members and 1 Guest are viewing this topic.

Offline jacobcolbert

  • Regular Member
  • ***
  • Posts: 10
  • Mole Snacks: +0/-0
Work done by a voltaic cell
« on: July 16, 2007, 03:00:10 PM »
I have been trying to find an expression for the work done by a voltaic cell online to no avail. My strategy for coming up with one was to rework the nernst equation to give the voltage difference as a function of the charge that has been transferred and then to integrate the function with respect to charge. My answer seems to make sense as it starts with nFE0 and is followed by a bunch of correction terms. If anyone could show me a formula for this or verify that my approach is viable it would be greatly appreciated.

Thanks,
Jacob

Online Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27652
  • Mole Snacks: +1800/-410
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Work done by a voltaic cell
« Reply #1 on: July 16, 2007, 03:40:08 PM »
You can try to approach the problem from thermodynamic side - what is free energy definition?
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline Yggdrasil

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 3215
  • Mole Snacks: +485/-21
  • Gender: Male
  • Physical Biochemist
Re: Work done by a voltaic cell
« Reply #2 on: July 16, 2007, 04:41:12 PM »
Well, from basic physics, P = IV where P is power (work/time), I is current, and V is the emf of the cell.

Online Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27652
  • Mole Snacks: +1800/-410
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Work done by a voltaic cell
« Reply #3 on: July 16, 2007, 05:05:07 PM »
Well, from basic physics, P = IV where P is power (work/time), I is current, and V is the emf of the cell.

As far as I understand, that's what he did, just taking into account fact that voltage changes with the reaction progress.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline jacobcolbert

  • Regular Member
  • ***
  • Posts: 10
  • Mole Snacks: +0/-0
Re: Work done by a voltaic cell
« Reply #4 on: July 16, 2007, 09:00:30 PM »
From a thermodynamic side i can set dG=nFE(X)dX where E(X) is the emf of the cell as a function of a product and dX is a differential product change right? I'll have to try this to see how it compares to my first one. Thanks.

Sponsored Links