1. The SDN iPhone App is back and free through November! Get it today and please post a review on the App Store!
    Dismiss Notice
  2. Dismiss Notice
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

electrochem question

Discussion in 'MCAT Study Question Q&A' started by echoyjeff222, Sep 7, 2014.

  1. echoyjeff222

    2+ Year Member

    Joined:
    Jun 17, 2013
    Messages:
    362
    Likes Received:
    52
    Status:
    Medical Student (Accepted)
    TBR passage XIV, number 90:

    upload_2014-9-7_20-36-26.png upload_2014-9-7_20-36-52.png

    I thought it was D because it directly says the final masses in the passage ... I don't get it? Is the time scale going past the 1 min in the experiment or something? I know the solution IV has a higher molarity, but I thought that would just result in a longer time of increasing mass ... help?
     
  2. Note: SDN Members do not see this ad.

  3. mehc012

    mehc012 Big Damn Hero
    5+ Year Member

    Joined:
    Jul 9, 2012
    Messages:
    9,106
    Likes Received:
    7,732
    Status:
    Medical Student
    Well, you know it must be B or D because 1 reaches a higher mass at the end, right?

    So the real question is, which proceeds more quickly? Which reaches the final mass first?

    We tend to ignore concentration in these things, but it does make a difference. Here, it is the only difference which you are given any information on...you are not given the reduction potentials, so you can't be expected to make a judgement based on that. You DO know that the concentrations differ. So, would the one with a higher concentration of reactant be expected to react more or less quickly?
     
    Cawolf likes this.

Share This Page