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Topic: I really need your help ON ESTERS!!!  (Read 3636 times)

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Offline angelz33

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I really need your help ON ESTERS!!!
« on: March 19, 2008, 12:32:13 AM »
I did an experiment which involved synthesizing esters by reacting alcohol and carboxylic acid together. We had some carboxylic acids and some alcohols, which we reacted together. So overall we had 7 test tubes having different esters in it.

Then we added sulfuric acid as a catalyst. Then we put the test tube in the water which was at the temperature 80 degrees Celsius (it was being heated).

After 10 minutes we took the test tubes out and put them in a big beaker filled with cold or normal temperatured water. This was done so that test tubes could cool down.

Then we added distilled water to each one of the test tubes.

We began to sniff the test tubes to identify their odors.

What are the possible errors in this experiment that could lead us to detect wrong smell or no smell?

 :-\ PLEase HELP..

Offline agrobert

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Re: I really need your help ON ESTERS!!!
« Reply #1 on: March 19, 2008, 02:45:49 AM »
First of all I'm not certain that you understand the experiment.

You are indeed generating esters.

http://en.wikipedia.org/wiki/Esterification

Generated by the condensation of a carboxylic acid with an alcohol under acid catalysis and heat.

In this reaction there exists an equilibrium between reactants and products.  Acid catalysis and heat pushes the reaction towards the formation of esters, which in turn have great fruity smells.

Even if your esters are not 100% pure, which most likely is the case the fruity smell of these compounds will indicate their presence qualitatively.

You should note improved smells for all esters relative to reactants.

Some carboxylic acids have foul or unpleasant odors.  Caproic acid smells like goats.
Alcohols can be pleasant but reminiscent of smells like acetone or nail polish remover.

http://en.wikipedia.org/wiki/Caproic_acid

The esters will most certainly be unique and enjoyable, but remember don't smell anything directly and for long duration.

http://en.wikipedia.org/wiki/Esters#Physical_properties

Look at all the odor possibilities.

In the realm of scientific observation, luck is only granted to those who are prepared. -Louis Pasteur

Offline Arkcon

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Re: I really need your help ON ESTERS!!!
« Reply #2 on: March 19, 2008, 07:53:07 AM »
You've asked a number of times why water is added to the test tube, after the reaction is complete.  Can you think of a reason involving the sulfuric acid you used as a catalyst?
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

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