1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Finding the pH of a buffer solution when a strong acid is added

  1. Feb 12, 2012 #1
    1. The problem statement, all variables and given/known data

    Three milliliters of a 2.0 M solution of HCL are added to 1 liter of buffer solution containing 0.40 moles of the weak acid, propanoic acid (Ka = 1.4 x 10-5) and .50 moles of its conjugate base, sodium propanate.

    1) find the ph of the buffer solution

    2) find the ph when the strong acid is added to the buffer solution

    2. Relevant equations

    Henderson Hasselbach equation: pH = Pka + log( A- / HA)

    3. The attempt at a solution

    1) to find the pKa -log(1.4 x 10-5) = 4.85
    pH = 4.85 + log(.4/.5) = 4.75
    is this correct?

    2) clueless
  2. jcsd
  3. Feb 13, 2012 #2


    User Avatar

    Staff: Mentor

    What happens when you add a strong acid? Is there any reaction taking place? How does it change concentrations of propanate and its conjugate acid?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Finding the pH of a buffer solution when a strong acid is added