Notices
Results 1 to 4 of 4

Thread: AP Chemistry Challenge

  1. #1 AP Chemistry Challenge 
    New Member
    Join Date
    Jun 2010
    Posts
    3
    AP-level Chemistry challenge question:

    Permanganic acid (350 ml of a 2.0M aqueous solution) is reacted with 2.0 L of 2.0 N hydrochloric acid, producing aqueous manganese (II) chloride and chlorine gas. The hydrochloric acid was made with pure radioactive chlorine-33, which has a half-life of 37.24 minutes and undergoes β− decay. The reaction is conducted in a sealed 25 L vessel at an initial pressure of 99.5 kPa. The vessel is kept at a constant temperature of 25C throughout the reaction. What is the pressure inside the vessel after 75 minutes? What assumptions need to be made when solving this problem?


    Reply With Quote  
     

  2.  
     

  3. #2  
    New Member
    Join Date
    Jun 2010
    Posts
    3
    ...and how does that help?


    Reply With Quote  
     

  4. #3  
    Moderator Moderator AlexP's Avatar
    Join Date
    Jul 2006
    Location
    NY
    Posts
    1,838
    Don't mind him, he's just a spammer. I deleted the post so no one links to his site.

    What thoughts have you had about this question? Have you made any progress on it?
    "There is a kind of lazy pleasure in useless and out-of-the-way erudition." -Jorge Luis Borges
    Reply With Quote  
     

  5. #4  
    New Member
    Join Date
    Jun 2010
    Posts
    3
    well i did the redox half reactions and combined them for an overall reaction of:

    MnO4- + 3Cl2 + 8H+ ---> Mn2+ + 4H20 + 6HCl-

    so there are 3 moles of gas in the system, and the beta decay, i assumed to be negligible, since it doesnt affect mass. so the initial number of moles, based on

    PV=nRT, is 1.004 moles, and since the equation tells us it is 3, I did a ratio to find a pressure of 0.329 atm. But i dont feel that this is correct, and that i forgot stuff
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •