December 10, 2019, 02:16:43 PM
Forum Rules: Read This Before Posting


Topic: How to measure the point when oxidation of alcohol occurs?  (Read 736 times)

0 Members and 1 Guest are viewing this topic.

Offline helpmeplsyeet

  • Very New Member
  • *
  • Posts: 1
  • Mole Snacks: +0/-0
How to measure the point when oxidation of alcohol occurs?
« on: March 30, 2019, 05:02:22 AM »
I want to conduct an experiment on the oxidation of ethanol to become ethanal but am unsure how to accurately measure it aside from observing a colour change. Is there some sort of quantitative way to notice that the reaction has occurred? The intent is to measure the reaction rate for the reaction to occur, so in order to accurately do so I've been told I need another way to measure it.

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 25361
  • Mole Snacks: +1663/-398
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: How to measure the point when oxidation of alcohol occurs?
« Reply #1 on: March 30, 2019, 07:37:17 AM »
Ethanal is colorless, so you won't see any color change. But you should be easily able to follow concentration changes with IR spectroscopy, oxidation means producing carbonyl, which is pretty characteristic.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info, pH-meter.info

Offline wildfyr

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 1376
  • Mole Snacks: +149/-9
Re: How to measure the point when oxidation of alcohol occurs?
« Reply #2 on: March 30, 2019, 06:40:13 PM »
There are colorimetric assays for aldehydes, you can use that to follow concentration by withdrawing little samples and doing a bit of math.

Offline Corribus

  • Chemist
  • Sr. Member
  • *
  • Posts: 2784
  • Mole Snacks: +443/-20
  • Gender: Male
  • A lover of spectroscopy and chocolate.
Re: How to measure the point when oxidation of alcohol occurs?
« Reply #3 on: March 31, 2019, 04:06:47 PM »
Aldehyde, like all carbonyl,  has a weak uv vis transition at about 280-290 nm that you could use, depending on the concentration. There is a much stronger one at around 190 nm or so but it is harder to use. Solvent cut off, cuvette type, and your instrument hardware are important to probe that far into uv.
What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent?  - Richard P. Feynman

Offline Babcock_Hall

  • Chemist
  • Sr. Member
  • *
  • Posts: 3909
  • Mole Snacks: +244/-16
Re: How to measure the point when oxidation of alcohol occurs?
« Reply #4 on: April 01, 2019, 01:44:44 PM »
The enzymatic oxidation is easy to follow in a continuous spectrophotometric assay.  However, this may not be something in which you are interested.

Sponsored Links