April 20, 2024, 12:31:00 PM
Forum Rules: Read This Before Posting


« previous next »
Pages: [1]   Go Down

Topic: Oxidation of Ethanol by Chromium (VI) calculations  (Read 1450 times)

0 Members and 1 Guest are viewing this topic.

Offline aoibhd

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Oxidation of Ethanol by Chromium (VI) calculations
« on: January 25, 2019, 07:09:34 AM »
If anyone could help me I would really appreciate it.
Im struggling to calculate the concentration of HCrO4- in the stock solution K2Cr2O7.
The concentration of the stock solution is 0.0037M in 3.6 M HCl.

Any help would be great,
Thanks,
aoibh
Logged

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27652
  • Mole Snacks: +1800/-410
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Oxidation of Ethanol by Chromium (VI) calculations
« Reply #1 on: January 25, 2019, 07:57:45 AM »
In concentrated HCl solution most of the chromic acid is already dehydrated to dichromate, so you will need to deal with a multistep equilibrium in a solution that has a very high ionic strength. It can be quite challenging to find out the exact equilibrium for such a solution.

What do you need it for?
Logged
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline aoibhd

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Re: Oxidation of Ethanol by Chromium (VI) calculations
« Reply #2 on: January 25, 2019, 08:27:57 AM »
I need the initial concentration in order to calculate the number of moles of HCrO4- during the oxidation of ethanol over time.
Logged

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27652
  • Mole Snacks: +1800/-410
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Oxidation of Ethanol by Chromium (VI) calculations
« Reply #3 on: January 25, 2019, 05:37:43 PM »
But why specifically HCrO4-? Why not Cr(VI) total?
Logged
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline chenbeier

  • Sr. Member
  • *****
  • Posts: 1348
  • Mole Snacks: +102/-22
  • Gender: Male
Re: Oxidation of Ethanol by Chromium (VI) calculations
« Reply #4 on: January 26, 2019, 01:39:58 PM »
Additionally dichromate will be reduced by HCl ,creating Chlorine.  Normaly sulfuric acid is used.

For the ethanol oxidation only the amount of Cr(VI) is neccessary.

Logged
Pages: [1]   Go Up
« previous next »
Sponsored Links