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!

Chemistry redox reaction - gases mixing

  1. May 6, 2014 #1
    1. The problem statement, all variables and given/known data
    How many milliliters of Cl2 gas, measured at 28.0 °C and 750 torr, are needed to react with 18.5 mL of 0.173 M NaI if the I- is oxidized to IO3- and the Cl2 is reduced to Cl-?


    2. Relevant equations



    3. The attempt at a solution

    So the molar mass is .0030906 mol NaI. Now I need to find out how many moles of Cl2 are needed to react completely with that.
    So I need the balanced chemical equation.

    Cl2 + NaI --> IO3- + Cl-

    Redox:

    2e- + Cl2 --> 2Cl-

    NaI --> IO3- + Na+

    This is where I get stuck.
    I can't balance NaI as a redox reaction because I don't know the charges on that side. How do I balance the second part of the reaction?
     
  2. jcsd
  3. May 6, 2014 #2
    Is 3Cl2 + NaI + 3H2O --> IO3- + Na+ + 6H+ + 6Cl-

    the correct balanced reaction?
     
  4. May 6, 2014 #3

    Borek

    User Avatar

    Staff: Mentor

    Technically - yes. But why don't you treat NaI as a dissociated salt (Na++I-), it is dissolved, isn't it?
     
  5. May 6, 2014 #4
    Ahh that's what was confusing me. I got the rest of it, thanks.
     
  6. May 6, 2014 #5
    ?

    what was the solution, im stumped
     
  7. May 7, 2014 #6
    So after you have the Redox reaction you have your ratio which is that for every 1 mol of NaI you have 3 moles of Cl2.

    You know that you have 18.5 mL of 0.173 M NaI so therefore

    .0185 L (.173 mol NaI/L) = moles of NaI.

    Now multiply that by three to get the moles of Cl2 because as shown from the balanced chemical equation - you need 3 moles of Cl2 for every 1 mol of NaI.

    From there you have

    PV=nRT

    Make sure to convert P to atm and T to Kelvin. n Is the amount of moles of Cl2 - solve for V. Done.

    Edit: oh yeah - convert to mL since that's what the question was asking for.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Chemistry redox reaction - gases mixing
  1. Redox reaction (Replies: 1)

  2. Redox Reactions (Replies: 4)

Loading...