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Homework Help: PH question

  1. May 20, 2008 #1

    rainbow-chick

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    [SOLVED] pH question....

    i'm writing a research paper on the organic medicinal massage oils. i need to know the chemical composition of citric acid and it's pH. can anyone help me???
     
    rainbow-chick, May 20, 2008
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  3. May 20, 2008 #2

    stewartcs

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    http://en.wikipedia.org/wiki/Citric_acid

    CS
     
    stewartcs, May 20, 2008
  4. May 21, 2008 #3

    Borek

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    Staff: Mentor

    There is no such thing as "pH of an acid". However, there is such thing as "pH of solution of the acid of known concentration". If you don't know concentration you can't say anything about pH. At best you may list dissociation constants.


    &
     
    Borek, May 21, 2008
  5. May 23, 2008 #4

    rainbow-chick

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    what i was really looking for was the pH of lemon juice i read somewhere that lemon juice was pure citric acid....?? sounds stupid now that i think about. sorry and thank you for your help!!
     
    rainbow-chick, May 23, 2008
  6. May 23, 2008 #5

    symbolipoint

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    "Pure citric acid" ---- nonsense since citric acid itself is a solid. Lemon juice is a liquid, a solution which contains a few solutes including citric acid. (Condition assumed, room temperature. ) Good thinking on your next thought shown from your message.
     
    symbolipoint, May 23, 2008
  7. May 25, 2008 #6

    rainbow-chick

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    well can anyone tell me the pH of lemon juice?
     
    rainbow-chick, May 25, 2008
  8. May 25, 2008 #7

    Gannon

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    Taken from Wikipedia (might want to double check credibility):

    "Lemon juice is about 5% (approximately .030 moles/Liter) citric acid, which gives lemons a tart taste, and a pH of 2 to 3."
     
    Gannon, May 25, 2008
  9. May 26, 2008 #8

    Borek

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    No, because it varies, depending on the fruit ripeness. That's what the first commercially available pH meter (Beckman's Model G) was made for - to help assess lemon ripeness.


    www.ph-meter.info
     
    Borek, May 26, 2008
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