tell me the tests... tollens , felings, DNPH, Iodoform ,

[Inert.Phantom]

please help me ... i want to know what reagnt is used to detect what...

 

[Mustehssun Iqbal]

2-4 DNPH detects the presence of Carbonyl group.
Tollen's reagent and Fehling's reagent either detect the presence of aldehyde or ketone.
Both aldehydes and ketones produces orange ppt with reaction with2,4- DNPH
Aldehyde produces red ppt with Fehling's reagent;
and gives silver with Tollen's reagent.
So 2,4 - DNPH is reacted with a sample. When the test shows positive result, test for the presence of aldehyde is done, that is, the sample is reacted with Tollen's reagent and Fehling's reagent. When the tests positive, that is, show the colour changes of the sample as mentioned, aldehyde is present . Otherwise, ketone is present. When the test with 2,4 - DNPH is negative, neither aldehyde or ketone is present.
P.s. revised it from here too: http://www.xtremepapers.com/community/attachments/4rauip-jpg.8834/

 

[TheMan123]

aldehydes-tollens and fehlings (or bennedicts)
tollens-silver mirror precipitate appears,
fehlinghs and bennedicts-from blue solution to brick red precipitate
carbonyls (aldehydes and ketones)-2,4-DNPH- yellow or orange or red precipitate appears
I dont know about iodoform I'm doing CIE AS Chemistry

 

[Apple Ipad64]

i've heard we'll get a question frm organic in the practl tmrow

 

[Muffy94]

i've heard we'll get a question frm organic in the practl tmrow

i have also heard the same..