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Topic: Iodoform Test and Acetophenone  (Read 13954 times)

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Offline shelley

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Iodoform Test and Acetophenone
« on: September 03, 2012, 05:45:18 PM »
The lab assistant was talking very fast, and I had to quickly write down the observation info. I would like to know if I recorded the correct observation and inference data for the Experiment or reaction on "Iodoform Test and Acetophenone", below? Thank you.
Acetophenone

   Observation:Bright yellow solution with solid suspended in bottom. No yellow ppte. When mixed there is a deep dark yellow ppte.   

Inference: Positive rxn. Presence of methyl ketone. There are two liquid phases and ppte was formed.

Offline shelley

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Iodoform Test and 2-butanol
« Reply #1 on: September 03, 2012, 06:10:15 PM »
Hi,

In the chemical rxn of Iodoform Test and 2-butanol do I have the correct observation and inference, below?  For the equation of the reaction should I draw the ring structure of the impurities in my lab report/write up?

Observation:   Turned cloudy with yellow ppte.
   
Inference: Positive rxn.  False positive test for methyl ketone.  Oxidizing agent positive results  can be interpreted as oxidized to methyl ketone:oxidizing agent effect.  When exposed to air solution was oxidized to form methyl ketone, so impurities are present.

Offline Arkcon

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Re: Iodoform Test and Acetophenone
« Reply #2 on: September 03, 2012, 06:39:55 PM »
Wikipedia has a description of the reaction here:  http://en.wikipedia.org/wiki/Iodoform_test#Iodoform_test  But either you've seen it in the lab, or you haven't.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline Vidya

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Re: Iodoform Test and Acetophenone
« Reply #3 on: September 04, 2012, 03:31:44 AM »
Wikipedia has a description of the reaction here:  http://en.wikipedia.org/wiki/Iodoform_test#Iodoform_test  But either you've seen it in the lab, or you haven't.
Hi,

In the chemical rxn of Iodoform Test and 2-butanol do I have the correct observation and inference, below?  For the equation of the reaction should I draw the ring structure of the impurities in my lab report/write up?

Observation:   Turned cloudy with yellow ppte.
   
Inference: Positive rxn.  False positive test for methyl ketone.  Oxidizing agent positive results  can be interpreted as oxidized to methyl ketone:oxidizing agent effect.  When exposed to air solution was oxidized to form methyl ketone, so impurities are present.


In this reaction you are using 2-butanol and carrying out iodoform test in which NaOH(or KOH) is mixed with CHI3.This solution is going to give a strong oxidizing agent which  oxidizes 2- butanol to 2-Butanone.CH3CH2CH2COCH3
it is a methy ketone and thats the reason you are getting a positive idoform test

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