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2002 - Q9

 

The following list of steps refers to an experimental plan for making an ester in a flask. Some of the steps in the list may NOT be required for this experiment. The steps are NOT in the correct sequence.

 

1. Heat the mixture under reflux

2. Add three drops of concentrated sulfuric acid

3. Add 1 mL of ethanol

4. Add 1 mL of ethene

5. Add 1 mL of ethanoic acid

6. Distil the mixture

7. Add three drops of phenolphtalein indicator

 

Which alternative is the best sequence for making an ester?

 

(A) 3, 5, 7, 1

(B) 4, 3, 7, 6

(C) 5, 4, 2, 6

(D) 5, 3, 2, 1

2001 - Q22 (6 marks)

 

Justify the procedure you used to prepare an ester in a school laboratory. Include relevant chemical equations in your answer.

2003 - Q21 (5 marks)

 

You performed a first-hand investigation to prepare an ester by reflux.

 

(a) Identify the products formed when propanoic acid and butanol are refluxed with acid catalyst. (1 mark)

 

(b)Draw a fully labelled diagram of the equipment assembled for use. (2 marks)

 

(c) Outline the advantages of using reflux to prepare the ester. (2 marks)

2002 - Q10

 

Which equation represents esterification?

2003 - Q25 (4 marks)

 

Explain the trends in boiling points shown in the graph.

2002 - Q11

 

A car engine burns fuel with insufficient air. Which substance would be emitted in the exhaust in higher levels than from an engine with a correct fuel to air ratio?

 

(A) Carbon dioxide

(B) Carbon monoxide

(C) Oxygen

(D) Water

2004 - Q1

 

Ethanol can be reacted with ethanoic acid to produce ethyl ethanoate. What type of reaction is this?

 

(A) Esterification

(B) Hydration

(C) Polymerisation

(D) Reduction

2005 - Q20 (7 marks)

 

The flow chart shows a series of steps involved in the production of ethyl butanoate.

 

glucose→ mixture containing ethanol→pure ethanol→ ethyl butanoate

 

Describe the chemistry and procedure involved in each of these steps, using diagrams where appropriate.

2007 - Q23 (3 marks)

 

When hexanoic acid and ethanol are mixed together under certain conditions, esterification occurs.

 

Describe the conditions necessary for this reaction and give the structural formulae and names of the products. (3 marks)

2009 - Q16 (3 marks)

 

Describe how to prepare an ester in the school laboratory. Include a specific safety precaution in your answer.

2004 - Q11

 

In gas chromatography, compounds may be separated based on their molecular weight. The smaller the molecular weight the more quickly the compound is detected. A gas chromatographic analysis was performed on a mixture of 1-hexanol, 1-octanol, 1-heptanol and 1-pentanol. The results are shown in the diagram.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Which substance does peak X correspond to?

 

(A) 1-hexanol

(B) 1-octanol

(C) 1-heptanol

(D) 1-pentanol

2005 - Q6

 

Which of the following is a common use for ethyl pentanoate?

 

(A) Flavouring

(B) Fuel

(C) Indicator

(D) Solvent

2010 - Q22 (6 marks)

 

A student prepared the compound methyl propanoate in a school laboratory.

 

(a) Give a common use for the class of compounds to which methyl propanoate belongs. (1 mark)

 

(b) In the preparation of this compound a few drops of concentrated sulfuric acid were added to the starting materials. The mixture was then refluxed for a period of time.

Why was it necessary to reflux the mixture? (2 marks)

 

(c) Name the TWO reactants used in preparing the methyl propanoate and draw their structural formulae. (2 marks)

2012 - Q21 (4 marks)

 

(a) Write a balanced chemical equation, using structural formulae, for the formation of ethyl butanoate. (2 marks)

 

(b) Common safety precautions in school laboratories include the use of safety glasses, gloves and lab coats. Justify the use of another safety precaution specifically required to safely make ethyl butanoate. (2 marks)

2013 - Q21 (6 marks)

 

(a) Why is acid used as a food preservative? (2 marks)

 

(b) Explain, on a labelled diagram, why reflux is used to produce an ester. (4 marks)

2014 - Q26 (6 marks)

 

A first-hand investigation to produce an ester is to be carried out in a school laboratory, using an alkanol, an alkanoic acid and a suitable catalyst.

 

(a) Name an ester that could be produced in a school laboratory. (1 mark)

 

(b) Describe how potential hazards associated with the three chemicals required for this investigation could be addressed. (5 marks)

2006 - Q7

 

Which class of compounds typically has a sweet smell?

 

(A) Esters

(B) Alkenes

(C) Haloalkanes

(D) Alkanoic acids

2008 - Q11

 

In which of the following alternatives are the three compounds listed in order of increasing boiling point?

 

(A) Pentane, butan-1-ol, propanoic acid

(B) Propanoic acid, butan-1-ol, pentane

(C) Propanoic acid, pentane, butan-1-ol

(D) Butan-1-ol, propanoic acid, pentane

2016 - Q22 (5 marks)

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This apparatus was set up to produce methyl butanoate.

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(a) Identify a safety issue in this experiment. (1 mark)

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(b) Using structural formulae, write the equation for the production of methyl butanoate. (2 marks)

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(c) Justify the use of apparatus X in this experiment (2 marks)

2009 - Q10

 

Which of the following is the main organic product resulting from the reaction of butanoic acid and pentanol?

2010 - Q14

 

The table shows information about three carbon compounds.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

What is the best estimate for the boiling point of compound Z?

 

(A) 31°C

(B) 101°C

(C) 114°C

(D) 156°C

2011 - Q8

 

What is the systematic name of the molecule shown?

 

 

 

 

 

 

 

(A) Butyl butanoate

(B) Propyl butanoate

(C) Butyl propanoate

(D) Propyl propanoate

2013 - Q18

 

Consider the following series of reactions.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Which row in the table correctly identifies Compounds X, Y and Z?

 

               Compound X             Compound Y             Compound Z

(A)             Propene                  Propan-1-ol          Ethyl propanoate

(B)             Propene                     Ethanol               Propyl ethanoate

(C)              Ethanol                    Ethylene               Propyl ethanoate

(D)             Ethylene                    Ethanol                Ethyl propanoate

2015 - Q9

 

What are the reactants used to make this compound?

 

 

 

 

 

 

 

(A) Butan-1-ol and butanoic acid

(B) Butan-1-ol and propanoic acid

(C) Propan-1-ol and butanoic acid

(D) Propan-1-ol and propanoic acid

2016 - Q3

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What is the molecular formula of pentanoic acid?

(A) C5H9O

(B) C5H10O

(C) C5H10O2

(D) C5H11O2

2017 - Q4

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Esterification can be carried out in a school laboratory using the equipment shown.

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How could the safety of the process shown be improved?

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(A) Place a stopper on top of the condenser.

(B) Add concentrated sulfuric acid to the flask.

(C) Change the direction of water flow through the condenser.

(D) Replace the Bunsen burner with an electric heating mantle.

2017 Q4.png
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