Question:

Adding strong acid to a buffer

by  |  earlier

0 LIKES UnLike

A beaker with 175 mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.1M. A student adds 7.30 mL of a 0.340M solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.76.

 Tags:

   Report

1 ANSWERS


  1. 5.00 = 4.76 + log [CH3COO-] / [CH3COOH]

    [CH3COO-] / [CH3COOH] = 10^0.24 = 1.74

    [CH3COO-] + [CH3COOH] = 0.1

    [CH3COO-] / [CH3COOH] = 1.74

    solving this system we get [CH3COO-] = 0.0635 M and [CH3COOH] = 0.0365 M

    Moles CH3COO- = 0.0635 x 0.175 = 0.0111

    moles CH3COOH = 0.0365 x 0.175 = 0.00639

    Now you forgot to say if the solution is an acid or a base so I can not answre at your question but I thing that this can help you

Question Stats

Latest activity: earlier.
This question has 1 answers.

BECOME A GUIDE

Share your knowledge and help people by answering questions.