posted by kim .
if ferric chloride was added to an unknown which happened to be benzophenone to identify if it has the phenol functional grp...will the sol'n turn purple (it contains the phenol) or yellow(does not contain phenol)?
Benzophenone is a ketone and ketones don't give a ferric chloride test UNLESS they form the enol tautomer. Does it form the enol? I did not find anything on the Internet to tell me if benzophenone will give a positive ferric chloride test or not. Couple that with the fact that not ALL enols/phenols give a positive ferric chloride test and that leaves me with the suggestion that you try this in the lab. Sorry I can't be of more help.