The Oxidation of Ethanol

The Oxidation of Ethanol

Ethanol is a primary alcohol and can be oxidized to either an

alderhyde or a carboxylic acid.

[IMAGE]CH3CH2OH + [O] CH3CHO + H2O

[IMAGE]CH3CH2OH + 2[O] CH3COOH + H2O

The purpose of this experiment is to oxidize ethanol and then to test

the product to determine whether it has been oxidised to ethanal or

oxidised to ethanoic acid.

Method

We added 6cm³ of water to a pear-shaped flask, then added 2cm³ of

concentrated sulphuric acid, and set up the apparatus as shown below,

but with a stopper in place of the dropping funnel. We ensured that

all the glass joints were greased.

[IMAGE]

We then had to make up a solution containing 5g of sodium dichromate

in 5cm³ of water and add 4cm³ of ethanol. We had tom pour this mixture

into the dropping funnel. We heated the acid in the pear-shaped flask

until it was almost boiling and then turned off the bunsen burner. We

then had to carefully remove the stopper and put the dropping funnel

into the correct position, as shown in the diagram. We then added the

mixture containing the ethanol at such a rate to maintain the boiling

of the mixture in the pear-shaped flask. We collected the distillate

and recorded our observations.

After collecting the distillate we had to do two tests to see whether

we had oxidised ethanol into ethanal or ethanoic acid.

The first test was to put 5 drops of the distillate into a test tube

and 5 drops of universal indicator solution.

The second test was to put 5 drops of the distillate into a test tube

and add a small amount of sodium carbonate.

Both of these tests were tests for carboxylic acids. The test for ...

... middle of paper ...

...owed a slight fizzing which

also shows the distillate is an acid.

Conclusion

After doing the experiment my results show that a carboxylic acid has

been formed. I have come to this conclusion as after doing both tests

with this distillate my results show an acid has been formed. It was

an oxidation reaction of a primary alcohol and with this reaction

either an alderhyde or carboxylic acid can be formed. The carboxylic

acid will have been formed as there would have been an excess of

dichromate. The equation for this reaction is:

[IMAGE]CH3CH2OH + 2[O] CH3COOH + H2O

I have made my decision as a carboxylic acid as two tests have shown

this and test 1 with the universal indicator proved it was an acid by

changing from colourless to red and test 2 showed fizzing which is

also the sign of an acid being formed.