February 08, 2023, 07:47:09 AM
Forum Rules: Read This Before Posting


Topic: drying of sodium phosphate  (Read 2844 times)

0 Members and 1 Guest are viewing this topic.

Offline HB

  • Regular Member
  • ***
  • Posts: 56
  • Mole Snacks: +1/-3
drying of sodium phosphate
« on: October 08, 2013, 01:15:05 PM »
I have trisodium phosphate dodecahydrate and I want to obtain anhydrous sod. phosphate. can I simply dry it in the oven

Offline Archer

  • Chemist
  • Sr. Member
  • *
  • Posts: 1001
  • Mole Snacks: +85/-20
  • Gender: Male
Re: drying of sodium phosphate
« Reply #1 on: October 09, 2013, 04:10:57 AM »
I have trisodium phosphate dodecahydrate and I want to obtain anhydrous sod. phosphate. can I simply dry it in the oven

I have no experience of this but I have had success with drying other hydrates in the oven.

You could try a 110°C oven for a few hours with a small (accurately weighed) quantity until you obtain a constant weight and then calculate the loss and see if it equals the correct weight of water as calculated from the mols of water present in the hydrate.
“ I love him. He's hops. He's barley. He's protein. He's a meal. ”

Denis Leary.

Offline Hunter2

  • Sr. Member
  • *****
  • Posts: 1895
  • Mole Snacks: +142/-45
  • Gender: Male
  • Vena Lausa moris pax drux bis totis
Re: drying of sodium phosphate
« Reply #2 on: October 09, 2013, 04:34:11 AM »
To get real anhydrous products, treat them with Thionyl chloride SOCl2. The Water will be decomposed to HCl and SO2. I t need a good hood with exhaust.

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27274
  • Mole Snacks: +1771/-408
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: drying of sodium phosphate
« Reply #3 on: October 09, 2013, 04:40:46 AM »
Just drying doesn't guarantee getting anhydrous salt, it is a matter of how strongly water molecules are kept by ions in the salt. Check if you will be able to find the thermogravimetric curve for the salt in question, it should tell you if and at what temperature phosphate becomes anhydrous.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info, pH-meter.info

Offline Hunter2

  • Sr. Member
  • *****
  • Posts: 1895
  • Mole Snacks: +142/-45
  • Gender: Male
  • Vena Lausa moris pax drux bis totis
Re: drying of sodium phosphate
« Reply #4 on: October 09, 2013, 05:14:37 AM »
Phosphates also have the risk to built up Polyphosphates.

Sponsored Links