ORGANIC CHEMISTRY – REVISION QUESTIONS

Question 1al Nov 2001

Consider the following organic compounds when answering the questions below:

A.C2H2D.C2H5OH

B.C2H4E.HCO2CH2CH3

C.C2H6F.HCO2H

1.1Which compound has two structural isomers? (Write down only the letter)(2)

1.2Write down the balanced equation for the reaction of compound C with excess oxygen.(3)

1.3Which compound is the product of the fermentation of grapes? (Letter only)(2)

1.4Which compound is used in welding? (Letter only)(2)

1.5Explain how you can experimentally distinguish between compounds B and C,(4)

1.6Write down the structural formula of the organic product of the reaction between compounds D and F.(3)

1.7Write down the systematic (IUPAC) name of the product in question 1.6(2)

1.8Write down the NAME of the catalyst that is generally used in the reaction between compounds D and F(2)

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Question 2National Nov 2002

Consider the following chemical substances A to G

A.C4H8B.ethane

C.bromineD.ethanoic acid

E.F.

G.

2.1Give the IUPAC systematic name of E.(2)

2.2Choose from the list a substance that is used in the laboratory preparation of E.(2)

2.3Give the NAME of the catalyst that is needed for the reaction referred to in 2.2.(2)

2.4Choose from the list a substance that is formed during the catalytic oxidation of G.(2)

2.5Write down the structural formula of three isomers of substance A.(6)

2.6Under each of the isomers in 2.5, write down its IUPAC (systematic) name.(3)

2.7By making use of structural formulae, write down an equation of an addition reaction that occurs between two of the substances from the list. (4)

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Question 3National Nov 2003

3.1Consider the following formulae of organic compounds:

A.C2H4

B.C2H6

C.C2H2

D.HCCl3

3.1.1Write down the equation, using structural formulae, for the reaction of compound A with bromine.(4)

3.1.2Compound B does not react with bromine as easily as compound A. Explain why this is so.(2)

3.1.3To which group (class) of compounds does compound D belong?(2)

3.1.4Write down the IUPAC name for compound D.(2)

3.2Ethanol is oxidized by potassium dichromate to form compound X. Compound X then reacts with ethanol, in the presence of a suitable catalyst, to produce an organic compound Y.

3.2.1By what process is ethanol produced from starch?(2)

3.2.2Write down the structural formula for compound X.(2)

3.2.3Write down the NAME of the functional group present in compound X.(2)

3.2.4Write down the IUPAC name for compound Y.(2)

3.2.5Write down the FORMULA of the catalyst used in the reaction between compound X and ethanol.(2)

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Question 4National March 2004

4.1A certain hydrocarbon contains two hydrogen atoms for every carbon atom. The relative formula mass of the compound is 42.

4.1.1Write down the molecular formula for this compound.(2)

This hydrocarbon is bubbled through a solution of bromine in an organic solvent.

4.1.2What is observed in this experiment.(2)

4.1.3What type of reaction took place.(2)

4.1.4Use structural formulae to write down an equation that explains the observation in question 4.1.2.(4)

4.2Consider the following organic compounds:

A.HCOOH

B.CH3COOH

C.HCOOCH2CH3

D.CH3CH2COOH

E.CH3CH2CH2OH

4.2.1Write down the structural formula for an isomer of E.(2)

4.2.2Write down the IUPAC (systematic) name of B.(2)

4.2.3Write down the functional group of C.(2)

4.2.4Write down the formula of the organic acid used in the preparation of C.(2)

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Question 5National Nov 2004

5.1For the following compound write:

5.1.1its IUPAC name.(2)

5.1.2the structural formulae of two of its isomers(4)

5.2The gas in an oxy-acetylene blowtorch burns in an excess of oxygen. Write a balanced equation for the reaction taking place. (3)

5.3Consider the following flow-diagram of a chemical process that leads to the formation of an ester:

5.3.1Ethanoic acid is obtained through the oxidation of compound A. Write the NAME of compound A(2)

5.3.2Write the NAME of compound B.(2)

5.3.3Give the IUPAC name and structural formula of the ester formed.(4)

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Question 6IEB Nov 2003

6.1What is a homologous series?(2)

6.2A mixture of Ethanoic acid and methanol is warmed in the presence of concentrated sulphuric acid.

6.2.1Using structural formulae give an equation for the reaction which takes place.(6)

6.2.2What is the IUPAC name of the organic compound formed in this reaction?(2)

6.3Consider the following unsaturated hydrocarbon:

6.3.1Give the IUPAC name for this compound.(2)

6.3.2Give the balanced equation for the combustion of this compound in excess oxygen.(4)

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Question 7IEB Nov 2004

The table below gives boiling points of ten organic compounds.

COMPOUND / FORMULA / BOILING POINT ºC
1 / methane / CH4 / -164
2 / ethane / C2H6 / -88
3 / propane / C3H8 / -42
4 / butane / C4H10 / 0
5 / pentane / C5H12 / 36
6 / methanol / CH3OH / 65
7 / ethanol / C2H5OH / 78
8 / propan-1-ol / C3H7OH / 98
9 / propan-1,2-diol / CH3CHOHCH2OH / 189
10 / propan-1,2,3 - triol / CH2OHCHOHCH2OH / 290

The following questions refer to the compounds shown in the above table.

7.1To which homologous series do the following compounds belong?

7.1.1Compounds 1,2 and 3(2)

7.1.2Compounds 6, 7 and 8(2)

7.2Which of the above compounds are gases at room temperature?(2)

7.3What causes the trend of increasing boiling points of compounds 1 to 5?(5)

7.4Despite the fact that the length of the carbon chain in compounds 8, 9 and 10 is the same, the boiling point of propan-1,2,3-triol is much higher than the boiling point of propan-1-ol. What is responsible for this large difference in boiling point? (2)

7.5Give the IUPAC name and the structural formula of an isomer of butane.(3)

7.6Which one of the above substances is used as a reactant in the preparation of the ester ethylmethanoate?(2)

7.7Using structural formulae, write an equation for the reaction which produces ethylmethanoate.(4)

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