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chemical equilibrium

Discussion in 'Off Topic [BG]' started by sargebaker, Mar 8, 2005.


  1. sargebaker

    sargebaker Commercial User

    May 2, 2004
    Montreal QC CA
    owner/builder, ISLAND Instrument Mfg.
    Does anyone know a basic lab experiment I could do on this chemical principal? I hate chemistry :crying:
     
  2. ((ZASDER))

    ((ZASDER))

    Feb 26, 2005
    Buffalo NY
    Do Like a simple Slat - Water or Suger - Water...

    Doesnt look like anything but...the same amount of salt going into water comes out at the same time...
     
  3. nonsqtr

    nonsqtr The emperor has no clothes!

    Aug 29, 2003
    Burbank CA USA
    Yeah, something with a "precipitate" sounds like a good basic demonstration. Take a chemical that's only "slightly" water soluble, and find a way to measure "how much of it" goes into solution, and how much stays out.
     
  4. sargebaker

    sargebaker Commercial User

    May 2, 2004
    Montreal QC CA
    owner/builder, ISLAND Instrument Mfg.
    would you mind elaborating this on this? How would I determine this?
     
  5. ((ZASDER))

    ((ZASDER))

    Feb 26, 2005
    Buffalo NY
    Get like.... 100ml of water...

    and pour like....15 grams of salt/suger into the water and Estimate how much has disovolved. Water can Only take a certain amount before it starts not to take and goes into equilbruim..in and out..in and out..even ratio.
     
  6. sargebaker

    sargebaker Commercial User

    May 2, 2004
    Montreal QC CA
    owner/builder, ISLAND Instrument Mfg.
    is that considered equilibrium? or just over saturation? I'm still a little confuzzled on the principle itself, I'll have to talk to ym teacher. i just read some stuff thats like for exampl if u mix CO + H20 ---> CO2 + H2 or somehting of the likes and it was saying how the reverse action happens as quickly as the forward rxn at a certain point.... jeez, why did i take science I'm pursuing a career in creative arts! :bawl:
     
  7. ((ZASDER))

    ((ZASDER))

    Feb 26, 2005
    Buffalo NY
    Ok and example of equilbruim

    You wont be able to do this because...YOu wont have the equipment

    Go into a stationary room at like freezing temp enough to freeze and ice cube...

    Get a bucket of water and stick some ice in...

    Ice WILL!! unfreeze and turn to water...

    But at the same time...water is freezing....it is an even ratio 1/1 Same amount of water unfreezing is freezin. So you will have the same ice cubes....Just its not the same water...You can NOt see this happening!
     
  8. nonsqtr

    nonsqtr The emperor has no clothes!

    Aug 29, 2003
    Burbank CA USA
    Oh, "reaction" equilibrium. Well, that's more specific. There's a lot of good demos in that area. You could do something like dissolve some copper sulfate in water, and measure the pH to estimate how much sulfuric acid is being generated. The easiest experiment would be something where the target ends up precipitating out (ie non-water soluble), so you could then remove it (through filtering or something), and watch it form again. Those are always visually cool.

    Here's a few links that might help:

    http://alex.edfac.usyd.edu.au/Methods/Science/Internet-chem-dems-expts.htm

    http://www.chemistrycoach.com/Links to chemistry_experiments.htm

    http://www.anachem.umu.se/cgi-bin/pointer.exe?Demonstrations

    http://www.uni-regensburg.de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/link.htm

    http://www-rohan.sdsu.edu/staff/drjackm/chemistry/chemlink/teach/teach4.html
     
  9. dlloyd

    dlloyd zzzzzzzzzzzzzzz

    Apr 21, 2004
    Scotland
    Is this high school chemistry?
     
  10. Brad Barker

    Brad Barker Supporting Member

    Apr 13, 2001
    berkeley, ca
    doing something with la chatlier's principle might be interesting. plus, it's proof that you are at equilibrium.

    find some reaction that is easy to do and measure concentrations (i guess--not a real chem person).

    then identify if it is endo or exothermic.

    then add heat.

    the equilibrium concentrations will shift because of the heat. this might be hard to measure, say, if the reaction requires a large amount of heat to shift equilibrium a small amount. there are probably good examples in your textbook...?
     
  11. If you do this make sure you use very little water. I've seen pounds and pounds of salt go into a bucket of water and it kept dissolving.
     
  12. It's gotten this far before anyone's said: "do 6 shots of Jim Beam straight up while sitting, wait 15 minutes, stand up, do the hokey pokey, turn yourself around"- that's what equillibrium is all about.
     
  13. dlloyd

    dlloyd zzzzzzzzzzzzzzz

    Apr 21, 2004
    Scotland
    There's a very nice (and colourful) example in my old textbook (Ebbing) involving HgI2 (orange precipitate) at equilibrium with HgI4(2-) (colourless solution). Add NaI solution, it removes the precipitate by adding iodide ions, forcing the reaction to the right, add NaClO, it reforms, as the iodide ions are oxidised to IO-.
     
  14. sargebaker

    sargebaker Commercial User

    May 2, 2004
    Montreal QC CA
    owner/builder, ISLAND Instrument Mfg.
    Thanks, that sounds like a good one, I'm going to have a talk with my teacher tomorrow and see what chemicals I could use. Yeah Le Chatelliers principal is what I was talking about. I also like the salt + water example and then adding heat. And yes it is highschool chemistry (grade 11). I don't think I have a textbook, we don't use it but I really can't remember if we were given one or not.

    Thanks Everyone