March 29, 2024, 09:52:06 AM
Forum Rules: Read This Before Posting


Topic: Salt plates in spectroscopy  (Read 4549 times)

0 Members and 1 Guest are viewing this topic.

Offline kb2009

  • New Member
  • **
  • Posts: 4
  • Mole Snacks: +0/-0
Salt plates in spectroscopy
« on: January 31, 2008, 11:11:15 AM »
In some IR spectra where the salt plates being used have been left out, a broad peak appears at around 3500 cm-1, even though the sample being analyzed does not contain an alcohol subsitituent

Why does this peak occur?

Offline Arkcon

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7367
  • Mole Snacks: +533/-147
Re: Salt plates in spectroscopy
« Reply #1 on: January 31, 2008, 11:53:50 AM »
You're not 'sposed ta leave the salt plates out?  Damn, I better wash 'em before the boss finds out.  What brand of soap do you use?

to O.P.: report all flaws in my responce
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline optimusprime

  • Regular Member
  • ***
  • Posts: 17
  • Mole Snacks: +2/-2
Re: Salt plates in spectroscopy
« Reply #2 on: January 31, 2008, 03:03:48 PM »
Salt plates are hygroscopic, and hence should be kept in a desiccator at all times.

Can you figure out what the O-H peak you're seeing is now?

Hint: It's water.

Offline ARGOS++

  • Sr. Member
  • *****
  • Posts: 1489
  • Mole Snacks: +199/-56
  • Gender: Male
Re: Salt plates in spectroscopy
« Reply #3 on: January 31, 2008, 04:15:06 PM »
Dear Optimusprime;

I agree with you (your Hint):  3600 – 3200 cm-1(s) a very broad band of “all” different Hydrogen bonds. (Rarely one or the other additional sharp peaks.)
Bond strength” corresponds ‘nicely’ with frequency-1.

Good Luck!
                    ARGOS++


Sponsored Links