November 27, 2024, 02:48:11 PM
Forum Rules: Read This Before Posting


« previous next »
Pages: [1]   Go Down

Topic: How do you measure a molecule's pka?  (Read 1706 times)

0 Members and 1 Guest are viewing this topic.

Offline ashika

  • New Member
  • **
  • Posts: 4
  • Mole Snacks: +0/-0
How do you measure a molecule's pka?
« on: December 10, 2014, 09:59:49 AM »
Hello everyone,

I'm trying to measure the pka of a small molecule in water. I dissolved some of this molecule in a sodium phosphate buffer solution of pH 7.3. and proceeded to adding HCl 0.1 M. I obtained asigmoid curve the point of inflection of which occurs at pH 4.6. Can I say that 4.6 is the pKa of my molecule is 4.6? Can you titrate pKa in a buffered solution? Should I redo my experiment in distilled water?

Thanks!
Logged

Offline Babcock_Hall

  • Chemist
  • Sr. Member
  • *
  • Posts: 5707
  • Mole Snacks: +330/-24
Re: How do you measure a molecule's pka?
« Reply #1 on: December 10, 2014, 10:42:53 AM »
There are others here with greater expertise, but I am concerned about the presence of phosphate buffer.  I would try again in DI water.
Logged

Offline Irlanur

  • Chemist
  • Full Member
  • *
  • Posts: 423
  • Mole Snacks: +32/-4
Re: How do you measure a molecule's pka?
« Reply #2 on: December 11, 2014, 10:15:56 AM »
why would you do that in buffer?
Logged
Pages: [1]   Go Up
« previous next »
Sponsored Links