March 28, 2024, 08:48:23 AM
Forum Rules: Read This Before Posting


Topic: Why does Fe and Cl2 form FeCl3 instead of FeCl2?  (Read 7656 times)

0 Members and 1 Guest are viewing this topic.

Offline Sophia7X

  • Full Member
  • ****
  • Posts: 248
  • Mole Snacks: +32/-4
  • Gender: Female
  • I, a universe of atoms, an atom in the universe.
Why does Fe and Cl2 form FeCl3 instead of FeCl2?
« on: October 17, 2012, 08:24:45 PM »
The oxidation potential for Fe--> Fe+2 is higher than Fe--> Fe+3 so wouldn't forming FeCl2 be more spontaneous than FeCl3?
Entropy happens.

Offline renjianan

  • Very New Member
  • *
  • Posts: 1
  • Mole Snacks: +0/-1
Re: Why does Fe and Cl2 form FeCl3 instead of FeCl2?
« Reply #1 on: October 18, 2012, 12:48:06 AM »
Because the ΔH (enthalpy of combustion) of forming FeCl3 is higher than forming FeCl2. It means FeCl3 is more stable in thermodynamic than FeCl2.

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27637
  • Mole Snacks: +1799/-410
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Why does Fe and Cl2 form FeCl3 instead of FeCl2?
« Reply #2 on: October 18, 2012, 04:07:23 AM »
The oxidation potential for Fe--> Fe+2 is higher than Fe--> Fe+3 so wouldn't forming FeCl2 be more spontaneous than FeCl3?

As long as FeCl3 formation is "spontaneous enough" it doesn't matter much - reaction won't stop half a way, unless there are serious reasons (like not enough chlorine) to do so.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Sponsored Links