I'm asking because there's a question asking:
how many moles of NaOH to add (NaOH is a strong base right?) to 1.0 L of 2.0 M HC3H5O2 (acetic acid) to have a pH of 1.8x10^-5. Also, pK(a) is 1.8x10^-5 ?
2007-03-18 17:31:34 · 3 answers · asked by Gc 1 in Science & Mathematics ➔ Chemistry
Acetic acid by itself is not a buffer, but when you add the NaOH to it you react some of the acetic acid to produce the salt. In your problem since the pH needed and pKa are the same, the salt concentration and acetic acid concentration have to be equal. To do this half the acetic acid has to react. Compute the NaOH required to do this.
2007-03-18 17:58:35 · answer #1 · answered by Peter Boiter Woods 7 · 1⤊ 0⤋
NaOH is a strong base. I don't believe acetic acid can be a buffer, because a buffer must consist of a strong base or strong acid w/ a salt. and I don't think acetic acid is one of the strong acids.
2007-03-18 17:43:12 · answer #2 · answered by S Jenkins 2 · 0⤊ 1⤋
normally you use a stronger acid to make a buffer, but yes you can use acetic acid to fix pH to a certain level. use the same equation you have in other buffer questions
pH = pKa + log ([A-]/[HA])
2007-03-18 18:18:17 · answer #3 · answered by shiara_blade 6 · 0⤊ 1⤋