Identification of an organic unknown
Aim:
My aim for this investigation is to identify doing simple chemical tests of different organic compounds containing one of the following functional groups such as:
* Alkenes
* Primary alcohol
* Tertiary alcohol
* Aldehyde
* Ketone
* Carboxylic acid
* Ester
* Phenol
I will take each of the functional group and identify a test to see if the functional group is present in a unknown organic compound.
Alkenes:
Alkenes are unsaturated hydrocarbons which at least have 1 carbon-carbon double bond (C=C). They have the general formula of CnH2n with the structural formula of: CnH2n . They have a planar shape with bond angles of 120. (http://en.wikipedia.org/wiki/Alkene)
The test I am going to do for alkene to identify if the alkene is present or not is a bromine water test, which means if the alkene is present it will decolourised bromine water.
Method:
* First I will add few drops of bromine water into a test tube.
* Then I will add few drops of unknown organic compound.
* Then I will shake the test tube.
If the alkene decolourized bromine water this means that alkene is present. The colour will change from orange to colourless.
Apparatus:
i. Test tube
ii. Bromine water
iii. Unknown organic compound
Equation:
(http://www.bbc.co.uk/schools/gcsebitesize/img/ch01008.gif)
Alcohols:
Alcohols are compounds in which one or more hydrogen atoms in an alkane have been replaced by an -OH group.
Primary alcohols:
In a primary (1°) alcohol, the carbon which carries the -OH group is only attached to one alkyl group.
Test:
Primary alcohols can be oxidised to either aldehydes or carboxylic acids depending on the reaction conditions. The oxidising agent used in these reactions is normally a solution of sodium or potassium dichromate (VI) acidified with dilute sulphuric acid. If oxidation occurs, the orange solution containing the dichromate (VI) ions is reduced to a green solution containing chromium (III) ions. (http://www.chemguide.co.uk/organicprops/alcohols/oxidation.html)
Aim:
My aim for this investigation is to identify doing simple chemical tests of different organic compounds containing one of the following functional groups such as:
* Alkenes
* Primary alcohol
* Tertiary alcohol
* Aldehyde
* Ketone
* Carboxylic acid
* Ester
* Phenol
I will take each of the functional group and identify a test to see if the functional group is present in a unknown organic compound.
Alkenes:
Alkenes are unsaturated hydrocarbons which at least have 1 carbon-carbon double bond (C=C). They have the general formula of CnH2n with the structural formula of: CnH2n . They have a planar shape with bond angles of 120. (http://en.wikipedia.org/wiki/Alkene)
The test I am going to do for alkene to identify if the alkene is present or not is a bromine water test, which means if the alkene is present it will decolourised bromine water.
Method:
* First I will add few drops of bromine water into a test tube.
* Then I will add few drops of unknown organic compound.
* Then I will shake the test tube.
If the alkene decolourized bromine water this means that alkene is present. The colour will change from orange to colourless.
Apparatus:
i. Test tube
ii. Bromine water
iii. Unknown organic compound
Equation:
(http://www.bbc.co.uk/schools/gcsebitesize/img/ch01008.gif)
Alcohols:
Alcohols are compounds in which one or more hydrogen atoms in an alkane have been replaced by an -OH group.
Primary alcohols:
In a primary (1°) alcohol, the carbon which carries the -OH group is only attached to one alkyl group.
Test:
Primary alcohols can be oxidised to either aldehydes or carboxylic acids depending on the reaction conditions. The oxidising agent used in these reactions is normally a solution of sodium or potassium dichromate (VI) acidified with dilute sulphuric acid. If oxidation occurs, the orange solution containing the dichromate (VI) ions is reduced to a green solution containing chromium (III) ions. (http://www.chemguide.co.uk/organicprops/alcohols/oxidation.html)