Assay of thiophosphoryl chloride (PSCl3)

[praveenpaliwal]

Good evng experts,

I have one query regarding to titration and that's why I m posted here. Plz help me to find out the right place for post specially for titrations.

I am analyzing thiophosphoryl chloride (PSCl3). How ever it can be analyze on GC -TCD and I am getting good response also. Now I need to determine assay by titrimetric analysis of PSCl3. AT this stage I am getting the problem. When I prepare the sample in water it reacts with water and fumes are generated of HCl. I have tried to dissolve the fume with more addition of water and attempt the argentometric titration but does not get the white precipitate. This because of the formation of H2S.


PSCl3 + 4 H2O ---------- > 3HCl + H2S + H3PO4

Can any one help me to identified how can I get proper assay value of PSCl3 by titration either argentometry or acid -base titrations.

Best regards
Praveen

[itspip]

If the HCl boils off in the reaction, but leaves the phosphoric acid, which I assume goes to completion, could you still run an acid base titration on the remaining weak acid? I would expect that some of the HCl might still be around, but possibly constructing a complete curve would allow you to chose one of the other protons on H3PO4.