AQA GCSE Chemistry

Topic Questions

7.2 Reactions of Alkenes & Alcohols

1a1 mark

This question is about alkenes.

The structure of propene is shown in Figure 1. 

Figure 1
aqa-gcse-7-2e-tq1a-propene


What is the molecular formula of propene? 

1b2 marks

Which two statements are correct about alkenes?

Tick (two boxes.

 Alkenes are saturated 

 

 Alkenes are unsaturated

 

 Alkenes have covalent bonds

 

 Alkenes are unreactive 

 

1c1 mark

The beginning of the general formula of alkenes is written below.

Complete the general formula of alkenes.

CnH___

 

1d1 mark

Alkenes can undergo incomplete combustion.

What is meant by incomplete combustion? 

1e2 marks

The following equation shows the incomplete combustion of ethene.

Name the two products formed in this reaction.

C2H(l)   +   2O2 (g)   →   2CO (g)   +   2H2O (l)

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2a1 mark

This question is about ethanol.

Ethanol belongs to the homologous series, alcohols.

Complete the structure of ethanol.

part-of-ethanol

2b2 marks

Ethanol can be used in alcoholic drinks.

Tick (two other uses of ethanol. 

 As fuels

 

 As polymers

 

 As solvents

 

 As perfumes 

 

2c2 marks

Why can ethanol not be referred to as a hydrocarbon?

2d3 marks

Ethanol is made by a process called fermentation.

Use the words in the box to complete the sentences on fermentation.

cool energy yeast warm
high oxygen carbon dioxide

During fermentation, sugar is converted to ethanol by adding ___________________. 

The reaction takes place at a ____________________ temperature in the absence of _____________________. 

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3a1 mark

This question is about carboxylic acids.

The structure of ethanoic acid is shown in Figure 1.

 
Figure 1

aqa-gcse-7-2e-tq3a-ethanoic-acid


Circle the functional group of ethanoic acid.

3b1 mark

Ethanoic acid can be formed from ethanol.

Which element does ethanol react with to form ethanoic acid?

Circle the correct answer.

 oxygen carbon  hydrogen
3c2 marks

Ethanoic acid will react with sodium carbonate in a neutralisation reaction.

Complete the word equation for this reaction:

ethanoic space acid space plus space sodium space carbonate space rightwards arrow space sodium space ethanoate space plus space _____________ space plus space _____________

3d2 marks

Ethanoic acid can dissolve in water.

Tick (two statements which correctly describe this reaction.

 Ethanoic acid partially ionises in water 

 

 Ethanoic acid releases OHions

 

 Ethanoic acid forms a solution with a pH of 1 

 

 Ethanoic acid is a weak acid 

 

3e1 mark

Ethanoic acid will react with ethanol to form an ester.

Name the ester formed from this reaction.

Tick (one box. 

  Ethene

 

  Ethyl ethanoate

 

  Ethane

 

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4a1 mark

This question is about the reactions of alkenes.

Which substance is an alkene?

Tick (one box.

 C5H12

 

 C7H14

 

 C12H20

 
4b1 mark

Alkenes are produced from the cracking of long chain hydrocarbons.

Give one use of the alkenes produced by this reaction.

4c3 marks

Ethene can react with hydrogen, water and chlorine due to the presence of the double bond. 

Draw one line to show the displayed formula of the product formed when ethene reacts with hydrogen, water and chlorine. 

 
aqa-gcse-7-2e-tq4c-reactions-of-alkenes-match-up
4d1 mark

Name the type of reaction that occurs when alkenes react with each substance in 4c. 

Circle one answer. 

Substitution Decomposition Addition Neutralisation

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5a4 marks

This question is about organic chemistry. 

Draw one line from each homologous series to the correct functional group.functional-group-match-up

5b4 marks

Complete each sentence about organic compounds by circling the correct word.

To test for the presence of an alkene you add

limewater.

bromine water.

litmus paper.

 

When sodium is added to ethanol

oxygen

carbon dioxide

hydrogen

is produced.

 

Propanoic acid will dissolve in water to give a solution with a pH of

4.

7.

13.

 

Esters, such as ethyl ethanoate are used 

as fuels.

in perfumes.

as solvents.

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1a1 mark

This question is about the reactions of organic compounds A - E shown in Figure 1. 


Figure 1 

organic-compounds-displayed-formulae

Name compound C. 

1b2 marks

Name one product formed when E reacts with sodium.

1c1 mark

Which compound reacts with compound A to produce compound C

1d1 mark

Give the catalyst needed for the reaction that produces compound D from compound B.

1e1 mark

Which compound dissolves in water to produce a neutral solution?

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2a2 marks

This question is about carboxylic acids.

The table below shows information about three carboxylic acids.

Complete the table. 

 Name  Formula 
 Ethanoic acid  CH3COOH
  CH3CH2CH2COOH
 Propanoic acid  

2b3 marks

Solutions of ethanoic acid and hydrochloric acid have different pH levels at the same concentration.

Explain the difference in pH levels between the two acids 

2c3 marks

A student adds sodium to a solution of ethanoic acid in an open flask on a balance.

Explain what happens to the mass of the flask and its contents during the reaction.

2d2 marks

In a separate reaction, a student adds ethanoic acid to zinc carbonate.

Describe and give the result of a test the student would do to identify the gas produced.

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3a1 mark

This question is about alcohols.

Alcohols have the general formula CnH2n+1OH.

Draw the displayed formula of propanol. 

3b3 marks

Alcohols undergo combustion reactions.

Write a balanced symbol equation for the complete combustion of butanol. 

3c3 marks

Figure 1 shows two methods of ethanol production. 

Figure 1

aqa-gcse-7-2h-tq3c-methods-of-ethanol-production


Explain how ethanol is made from sugar solution.

Give the name of the process. 

3d3 marks

Describe the conditions needed to convert ethene to ethanol. 

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4a6 marks

This question is about the reactions of organic compounds.

A flow chart of different reactions involving organic compounds is shown in Figure 1. 

Figure 1

aqa-gcse-7-2h-tq4a-organic-compounds-flow-chart


Name the type of reaction which occurs at:

   A: _________________________

   B: _________________________

   C: _________________________

   D: _________________________

   E: _________________________

   F: _________________________

4b1 mark

What type of chemical is used as a catalyst in reaction D? 

4c1 mark

Which is the correct structure of ethyl ethanoate?

Tick (one box. 



aqa-gcse-7-2h-tq4c-ethyl-ethanoate-tick-box
4d1 mark

Why can ethyl ethanoate be described as volatile?

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5a1 mark

This question is about alkenes.

Draw the displayed formulae of butene.

5b6 marks

The structures of an alkane and an alkene are shown below.

Compare the structures and reactions of propene with propane.

aqa-gcse-7-2h-tq5b-propene-and-propane

5c2 marks

Write a balanced symbol equation for the incomplete combustion of ethene to form carbon monoxide and water.

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1a3 marks

The equation shows the cracking of a long chain hydrocarbons.

         C29H60   →   C11H24   +   C11H22   +   C4H8   +   C3H6

One of the products formed is a different type of hydrocarbon to the other products. 

Give the formula for this product and explain why the chemical formula of this compound is different to the others. 

You should include the name of the family of compounds.

1b4 marks

Ethanol is produced from the reaction of ethene and steam in the presence of a hot catalyst. 

Add the missing bonds to complete the displayed structures in Figure 1.

Figure 1

7-2-reactions-of-alkenes--alcohols-medium-q1b

1c1 mark

Ethanol can also be produced by the fermentation of sugars from plants. 

Draw a ring around the temperature that is most suitable for this process.

10 °C

25 °C

350 °C

1d2 marks

Ethanol produced by fermentation is often added to petrol to create a biofuel. 

Explain why increasing the use of biofuels may cause food shortages.

1e2 marks

Burning biofuels contributes less to climate change than burning fossil fuels. 

Explain why.

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2a2 marks

This question is about organic compounds.

Ethanol is an alcohol and is used in the production of alcoholic drinks.

Give two other uses of ethanol.

2b1 mark

Which gas is produced when sodium reacts with ethanol?

2c2 marks

Ethanoic acid is a carboxylic acid which can be produced from ethanol,  CH3CH2OH.

State what type of reaction occurs in this process and complete the diagram to show the displayed formula for ethanoic acid in Figure 1.

Figure 1

ch3-group

2d4 marks

Solutions of hydrochloric acid and ethanoic acid have different pH values even though their concentration is the same.

Explain why the solution of hydrochloric acid has a lower pH than the solution of ethanoic acid. 

2e2 marks

Ethanoic acid and ethanol react in the presence of a catalyst to form an ester.

Give the name of the ester made from ethanol and ethanoic acid and identify the catalyst used in the process.

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3a2 marks

Cars can be powered by ethanol or ethanol–petrol mixture

To obtain ethanol, sugar cane can be fermented to give a mixture of water (boiling point 100 °C) and ethanol (boiling point 78 °C).

What process is used to separate ethanol from water and what physical property allows for it to work?

3b2 marks

Ethanol burns and gives out heat energy during complete combustion. 

Complete the formula of the products and balance the equation

___C2H5OH        +           ___O2      →      ______       +        _______

3c2 marks

During the production of ethanol, the vapour of an alkane is passed over a hot catalyst as shown in Figure 3. 

Figure 3

straight C subscript 6 straight H subscript 14 space rightwards arrow with Hot space catalyst on top straight C subscript 2 straight H subscript 6 plus 2 straight C subscript 2 straight H subscript 4
Hexane space space space space space space space space space space space space space space space space space space space Ethane plus Ethene


Name this process and explain why it is carried out. 

3d2 marks

Ethene can be used to produce ethanol.

Draw the displayed formula for ethene and name the compound that is added to ethene to produce ethanol.

3e6 marks

As explained in parts (a) and (c), ethanol can be made using either an alkane or sugar as the starting material.

Evaluate the advantages and disadvantages of using both of these two starting materials for the production of ethanol.

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4a1 mark

This question is about the reactions of alkenes and carboxylic acids.

Halogens react with alkenes.

Name this type of reaction.

4b2 marks

Name two other substances which also react with alkenes in this way.

4c1 mark

Butanoic acid is a carboxylic acid with the formula CH3CH2CH2CO2H. 

Write down the functional group of the carboxylic acids.

4d2 marks

Butanoic acid reacts with magnesium carbonate to form magnesium butanoate and two other products.

Complete and balance the equation for the reaction.

C4H8O2       +         MgCO3     →      C4H6OOMg     +         ______      +       ______

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