June 17, 2019, 01:23:12 PM
Forum Rules: Read This Before Posting


Topic: portland cement  (Read 12714 times)

0 Members and 1 Guest are viewing this topic.

Offline Rayan

  • Chemist
  • Regular Member
  • *
  • Posts: 56
  • Mole Snacks: +5/-14
  • Gender: Female
portland cement
« on: November 15, 2007, 05:29:26 PM »
Hi,
we had a lab today but i didn't really understant what were doing and why.. When i asked the Dr, he talked and talked and talked and didn't answer my question :s
we took a sample of white portland cement, to which we added ammonium chloride, and then hydrochloric acid. i understood that it's something about the fact that SiO2 is not soluble in the solution and precipitates, we filtrated the solution and then we had to weight the SiO2 to determine its percentage in our sample. did i get it right?? if yes, what are the reactions occuring? is there any websites that might help me?
thanks in advance :)

Offline ARGOS++

  • Sr. Member
  • *****
  • Posts: 1489
  • Mole Snacks: +199/-56
  • Gender: Male
Re: portland cement
« Reply #1 on: November 18, 2007, 12:17:30 PM »
Dear Rayan;

Yes! – You are doing right.

For SiO2:
As first reaction the also first & second reactions under “Hardening” on:       - takes place (Maybe the Ammonium chloride gives a better precipitation.)
The use of HCl speeds up the reaction and builds the soluble Calcium Chloride.
Therefore take a look under:  "Calcium Chloride

Good Luck!
                    ARGOS++
Formulas, in its best sense,  ARE ONLY Recipes for “A Picture”,  —
     If you DON’T catch “The Picture”, you are lost, - for ever!      (A++)

There is ONLY one correct Formula for the “Hydrogen”:  —
     The Atom/Molecule, ITSSELF!                          (Dr. R. Mory  1968)

"Make it AS SIMPLE AS possible,  — BUT NEVER SIMPLER!"  (A. Einstein)

Sponsored Links