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Homework Help: Naoh in sodium acetate, raise pH

  1. Sep 6, 2012 #1
    I need someone to tell me if I did this right....

    What volume of 10N NaOH should be added to 0.1L of 1 M sodium acetate pH 5.5 to change the pH to 6.0.

    so I'm assuming that there is also an amount of acetic acid in this solution for it to have an acidic pH right? So is it a buffer?

    In which case,

    5.5 = 4.76 + log (1M NaOac / x M Oac)

    and so x is 0.182 M acetic acid. or .0182 moles

    to raise the ph to 6

    i'm assuming it will take away a certain amount from acetic acid and add a certain amount to sodium acetate....so...

    6 = 4.76 + log( 0.1 + x / 0.0182 - x)

    and solving for x gives me 0.01177 moles of NaOH which is 0.001 Liters of 10 M NaOH.

    These numbers look awful to me so I feel like I did this wrong. Is this right?
  2. jcsd
  3. Sep 7, 2012 #2


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    Gold Member

    NaOH is very strong base and only few drops can make the solution basic, so I don't think the answer might be wrong. Better if I try it myself.
  4. Sep 7, 2012 #3


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    Staff: Mentor

    Logic is correct. I have not checked the numbers, but they don't look absurd to me. Just note you have to give higher accuracy - 0.01177 moles is not 0.001 L. More like 1.177 mL or rather 1.2 mL (0.0012 L) to keep the reasonable number of significant digits.
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