[migueldario]

hello

i was making a practice of identification of organic compounds and pass the following:

i had aqueous sample a basic pH so i figured it must be a salt of a carboxylic acid so to regenerate the acid add concentrated hydrochloric acid and a precipitate formed which was then filtered and purified.

after that leave it in an oven for approximately 20 hours and when I went to find there was no sign

I think if there was no sign must be due to Sublimated then my question is this: that carboxylic acids have the property to sublimate at temperatures of about 60 º C?

thanks

excuse my English

[POSEIDON]

hello

i was making a practice of identification of organic compounds and pass the following:

i had aqueous sample a basic pH so i figured it must be a salt of a carboxylic acid so to regenerate the acid add concentrated hydrochloric acid and a precipitate formed which was then filtered and purified.

after that leave it in an oven for approximately 20 hours and when I went to find there was no sign

I think if there was no sign must be due to Sublimated then my question is this: that carboxylic acids have the property to sublimate at temperatures of about 60 º C?

thanks

excuse my English

First sorry about my poor english, second check melting points chart of carboxilics acids in a handbook (CRC HANDBOOK of tables for ORGANIC COMPOUND IDENTIFICATION 3rd Ed ZVI RAPPOPORT).
 

[tmartin]

Just curious, but why did you need to place it in an oven for 20h?  Ideally the acid base extraction should leave your acid relatively pure, did you then further purify by recrystallization of column chromatography?  If so, I think it would be possible to remove residual solvent under reduce pressure for a few hours (a rotovap or high vacuum pump).  Perhaps prolonged heating led to decomposition of the compound?

From the orgo lab I TA'd a few times, if I recall correctly most of the common organic acids (based off benzoic acid) had melting points around or above 100 C, so I don't imagine sublimation would be a problem.  Each acid is going to be different, though.