Dismiss Notice

Interview Feedback: Visit Interview Feedback to view and submit interview information.

Interviewing Masterclass: Free masterclass on interviewing from SDN and Medical College of Georgia

Dismiss Notice
Hey Texans—join us for a DFW meetup! Click here to learn more.

(gen chem) whats the difference ?

Discussion in 'MCAT Study Question Q&A' started by doxycycline, Jan 6, 2009.

  1. swamprat

    Physician Classifieds Approved 10+ Year Member

    Joined:
    Jul 25, 2008
    Messages:
    1,617
    Likes Received:
    136
    Status:
    Attending Physician
    I remember seeing this formular: EMF = Ecat -Eanod

    But now I also see EMF = Eox + Ered.

    Did I just make that first equation up? I def saw it somewhere I can't find it in my review book though.
     
  2. Note: SDN Members do not see this ad.

  3. futuredoctor10

    Classifieds Approved 10+ Year Member

    Joined:
    Jan 25, 2007
    Messages:
    1,651
    Likes Received:
    14
    Status:
    Resident [Any Field]
    These are just two conventions for writing the EMF formula but both work.

    If you write the two equations (half-reactions) so that one is undergoing reduction and one is undergoing oxidation, and you change the value of E by inverting the sign, then you can just add the electric potentials.
    ** if reactions are written so that they are undergoing reduction (convention), you would flip the reaction [so it will undergo oxidation from L-->R] AND flip the sign.

    If you identify two half-reactions but DO NOT flip the reaction/sign, then you need to use EMF = Ecat -Eanod.

    Does that make sense?
     

Share This Page