nightflight - 23-5-2006 at 04:38
Hello to all of the board,
assuming having a reaction messed up, by ignoring a single step -which was adding too much water, like a bit more than twice as much, and now having
the reagents alltogether in the flask.
What can I do about it?
Can an excess of water + reagent A & B harm the reaction or the formation of product "C"?
Shall the reaction be stopped, the product extracted and then reacted again with proper molar ratio?
Your opinion please,
nightflight
[Edited on 23-5-2006 by nightflight]
DrP - 23-5-2006 at 04:54
It would depend on the reaction - If the water is just the medium or solvent whithin which the reaction was taking place then you might be alright.
If the water is taking part in the reaction itself then I would presume not. What is the reaction?
nightflight - 23-5-2006 at 05:07
it called for acid-reflux ... .
nightflight - 23-5-2006 at 05:35
there was a dry reaction set-up and a wet reflux , so I think I messed up those two.
The reaction shoud have been like a 57% acid reflux in a 1:1 molar ratio to the reagent, so assuming that the acid is too weak now, but water is not
necesseraly needed, as the hdyrogen will be build under dry condtitions during the reaction also, what would be a promising remedy to succesfully end
the reaction?
A longer reflux does´t sound too good, cause whre no reaction´s taking place, time will not do the job.
So maybe the acid should be as strong as it should be as an excess of ot shouldn´t hurt the product in a reduction?
leu - 23-5-2006 at 06:12
You need to isolate your reagents and start over as reduction cannot occur when the acid concentration is too low 
nightflight - 23-5-2006 at 06:49
And if the ph was corrected? -if that´s possible with the H20, cause the dry reaction didn´t use H2O while the wet reflux set-up was with a befor
prepared acid, I mean, it can´t be this easy?
[Edited on 23-5-2006 by nightflight]
nightflight - 23-5-2006 at 11:19
Maybe the treahd should be moved to another forum.
I think there´s a fault with the in situ formation of hydrooodic acid within a reduction, thinking that adding more rp and iodone out of the ratio to
the reagent would form more hydryoodic acid -what do you think?
I´ll have to go antoher way, if this reaction failed anyway, since I have not the chemicals to syntethise HI .
[Edited on 23-5-2006 by nightflight]
leu - 23-5-2006 at 17:39
If you can get the acid concentration up to over 50%, you can proceed with the tedious but effective long wet reflux 
If you don't have enough reagents to do this, you would be better off recovering
your reagents and start over with the proper ratios
nightflight - 27-5-2006 at 18:02
I could, I did some reading on it at wikipedia.
Excessive acid isn´t elgant but possible, of curse, but a waste.
Yield sucked for various reason, which I´think have been localized and will be avoided next time.