AS LEVEL CHEMISTRY

PAPER 2
PRACTICE PAPER 19
(structured questions only)
Answer all questions
Max 80 marks

	
Name		……………………………………………………………..

	
Mark		……../80	……....%	Grade ………
		
Note – this paper only contains structured questions

1.	

(Total 5 marks)
	
2.	

(6)	

	
    
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(4)	

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(5)
(Total 15 marks)	

3.	Compound X is shown below. It is a member of a homologous series of hydrocarbons.
				
(a)     (i)      Deduce the general formula of the homologous series that contains X.
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(1)
(ii)     Name a process used to obtain a sample of X from a mixture containing other members of the same homologous series.
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(1)
(b)     There are several isomers of X.
(i)      Give the IUPAC name of the position isomer of X.
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(1)
(ii)     Draw the structure of a functional group isomer of X.

 
(1)
(c)     At high temperatures, one molecule of C15H32 can be converted into two molecules of X and one molecule of another compound.
(i)      Write an equation for this reaction. 
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(1)
(ii)     State the name of the process used to obtain a high yield of X from C15H32 
Give one reason why this process is used in industry.
Name ....................................................................................................
Reason .................................................................................................
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(2)
(iii)    State why high temperatures are needed for this process.
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(1)

(d)     Compound X can be converted into compound Y.
Compound Y is shown below.

(i)    Write an equation to show the reaction of Y in a limited supply of air to produce a solid and water only. 
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(1)
(ii)    When a sample of Y, contaminated with CH3SH, is burned completely in air, a toxic gas is formed.
Identify this toxic gas and suggest a compound that could be used to remove the toxic gas from the products of combustion.
Toxic gas ..............................................................................................
Compound used to remove toxic gas ..................................................
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(2)
(iii)     Suggest the name of the process that occurs when the toxic gas in part (d)(iv) is removed.
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(1)
(e)     Explain why the boiling points of X and Y are similar.
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(2)
(Total 14 marks)

4.      (a)     Hexane (C6H14) is a hydrocarbon which is a component of LPG (liquid petroleum gas), used as a fuel for heating. When burning fuels in boilers it is important to ensure complete combustion.
(i)      Give two reasons why boilers are designed to ensure complete combustion.
Reason 1 ............................................................................................
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Reason 2 ............................................................................................
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(ii)     Write an equation for the incomplete combustion of hexane.
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(iii)     Suggest how an engineer or a chemist could demonstrate that the combustion of hexane in a faulty boiler was incomplete.
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(5)
(b)     Branched chain alkanes are often preferred as fuels. Draw the structure of two branched chain isomers of hexane and name the first isomer.

                                        Isomer 1                                           Isomer 2
Name of isomer 1 ........................................................................................
(3)
(c)     Hexane can be cracked in the presence of a catalyst to produce another hydrocarbon, Z, and methane.
(i)      Draw a possible structure for Z.

(ii)     Give a suitable catalyst for this reaction.
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(iii)     Suggest why the product Z has more commercial value than hexane.
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(3)

(d)     The overall equation for the production of dichloromethane from methane and chlorine is shown below.
CH4 + 2Cl2 → CH2Cl2 + 2HCl
(i)      Calculate the % atom economy for the formation of CH2Cl2 in this reaction.
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(ii)     Give one reason why this atom economy of less than 100% is an important consideration for the commercial success of this process and predict how a chemical company would maximise profits from this process.
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(3)
(Total 14 marks)
 
5.		

6.	

(Total 8 marks)

7.	

    A …………………………………………………………………………………………………………………………………………………………………     
    
    B …………………………………………………………………………………………………………………………………………………………………

    D …………………………………………………………………………………………………………………………………………………………………                
 (3)

    Name of mechanism:………………………………………………………………………………………….

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    Name of mechanism:………………………………………………………………………………………….

 
(5)

    Name of mechanism:………………………………………………………………………………………….

(3)
(Total 15 marks)	
8.