This site is supported by the advertisements on it, please disable your AdBlocker so we can continue to provide you with the quality content you expect.
  1. We are after as many aquarium plant images that we can get, doing so will assist us in completing the aquarium plant database.

    https://barrreport.com/threads/aquatic-plant-images-wanted.14374/
    Dismiss Notice

Molar concentration of HCO3-

Discussion in 'CO2 Enrichment' started by Anti-Pjerrot, Jan 10, 2008.

  1. Anti-Pjerrot

    Anti-Pjerrot Prolific Poster

    Joined:
    Apr 5, 2006
    Messages:
    62
    Likes Received:
    0
    Local Time:
    8:45 PM
    What is the molar concentration of HCO3- equal to 4kH?

    Ive looked at some different explainations, but ive found no clear answer, and it confuses me...

    There was a scheme with recalculations of kH somewhere...
     
  2. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,673
    Likes Received:
    623
    Local Time:
    8:45 PM
    4 KH = 71.44 ppm or mg/L.

    HCO3 per mole = 1+12+16*3 = ~61 grams per mole.

    So about 71.44/61 = a little over 1

    Regards,
    Tom Barr
     
  3. Anti-Pjerrot

    Anti-Pjerrot Prolific Poster

    Joined:
    Apr 5, 2006
    Messages:
    62
    Likes Received:
    0
    Local Time:
    8:45 PM
    4 kH = 0,0744g/L (You forgot to calculate mg to g)

    So 4kH equals 0,001171147M of NaHCO3, and if i wanted to test my kH 4 solution...

    I would titer my kH 4 solution with a 0,1000M HCl, and i should use 11,71mL HCl/L right?
     
  4. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,673
    Likes Received:
    623
    Local Time:
    8:45 PM
    Well, there abouts, I do not think you need to be so accurate here.
    Most use sodium carbonate for KH solutions.

    Regards,
    Tom Barr
     
  5. Anti-Pjerrot

    Anti-Pjerrot Prolific Poster

    Joined:
    Apr 5, 2006
    Messages:
    62
    Likes Received:
    0
    Local Time:
    8:45 PM
    But if i wanted to make a 4,00 kH solution, i need som accuracy.

    Im making a batch with 0,2495g of dried NaHCO3 (200ºC for 45min) dissolved in 2,0 L MQ water.

    That should give me roughly a kH 4 solution.

    Then i would just titer it with HCl to find the exact concentration, and adjust it with more MQ water/NaHCO3.

    Or is there an easier method to make kH 4,00 without a standard solution.

    I got all the lab equipment possible (well almost)

    If you got an easier method im all ears. :)
     
  6. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,673
    Likes Received:
    623
    Local Time:
    8:45 PM
    Using sodium carbonate, not bicarbonate. Less issues with drying/heaqting driving off some of ref powder.

    And of course, checking your ahem, units from mg to grams.
    I might make a mistake:)

    You can also buy pre made ref samples.

    Regards,
    Tom Barr
     
  7. Anti-Pjerrot

    Anti-Pjerrot Prolific Poster

    Joined:
    Apr 5, 2006
    Messages:
    62
    Likes Received:
    0
    Local Time:
    8:45 PM
    So what is the recipe for a 4,00 kH solution using sodiumcarbonate?
     
Loading...

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice