2005-2006 F5 Chemistry Test VII
(Time allowed: 40 minutes)
Name: ______________________ (
25-1-2006
)
F5(
)
Mark: ________________
Section A: Multiple Choice (10 marks)
Each question below (Questions Nos. 1 to 4) consists of two separate statements. Decide whether
each of the two statements is true or false; if both are true, then decide whether or not the second
statement is a correct explanation of the first statement. Then select one option from A to D
according to the following table:
Both statements are true and the 2nd statement is a correct explanation of the
1st statement
Both statements are true but the 2nd statement is NOT a correct explanation
of the 1st statement
The 1st statement is false but the 2nd statement is true.
Both statements are false.
A
B
C
D
1st statement
2nd statement
1.
Bromine can react with hexane in the presence of
sunlight.
The reaction between bromine and hexane is a
substitution reaction.
2.
Wax is a thermoplastic.
Wax can be softened by heating and hardened by
cooling.
3.
Anodizing aluminium increases the corrosion
resistance of aluminium.
Aluminium oxide layer on the metal surface is
thickened by anodization.
4.
Both dry ice and quartz exist in the form of
discrete molecules.
Carbon and silicon atoms have the same number of
electrons in their outermost shells.
5.
Which of the following substances can be used to distinguish between concentrated nitric acid and
concentrated sulphuric acid?
(1) sodium carbonate powder
(2) copper turnings
(3) cane sugar
6.
A.
(1) and (2) only
B.
(1) and (3) only
C.
D.
(2) and (3) only
(1), (2) and (3)
The melting point of the thermosetting plastics is high. What kind of force is present between the polymer
chains in thermosetting plastics?
A.
Covalent bond
B.
van der Waals’ forces
C.
D.
Ionic bond
Cohesive force
2005_F5_T7
1
7.
Which of the following picture represents the structure of Terylene?
H
A.
H
C
O
C
H
O
O
C.
O
O
C
C
O
O
C
C
8.
O
C
H
B.
D.
H
H
O
C
H
O
O
O
H
O
O
N
N
H
H
O
O
C
C
O
O
C
C
O
O
N
N
H
H
What is the number of bonded electrons in 35.5 g of chlorine gas at room conditions?
(Relative atomic mass: Cl = 35.5, Avogadro number = 6.02  1023 mol-1)
9.
A.
1.51  1023
B.
3.01  1023
C.
6.02  1023
D.
1.20  1024
Which of the following statements about a solution of hydrogen chloride in methylbenzene is/are correct?
(1)
It turns dry blue litmus paper red.
(2)
When anhydrous calcium carbonate is added, carbon dioxide is not evolved.
(3)
It can conduct electricity.
A.
(1) only
B.
(2) only
C.
(3) only
D.
(1), (2) and (3)
10. Which of the following set-up below can produce an electric current?
A.
B.
A
Cu
Fe
C.
D.
A
Fe
2005_F5_T7
Fe
NaCl(aq)
A
Cu
Fe
NaCl(aq)
2
Section B (30 marks)
For question 1, candidates are required give a paragraph-length answer. In this question, 6 marks
will be awarded for chemical knowledge and 3 marks for effective communication.
1. State the different behaviour of thermoplastics and thermosetting plastics towards heat respectively. AND
explain in terms of the structure, why nylon is a thermoplastic.
(9 marks)
2.
The repeating unit of nylon 6.6 is shown below:
H
N
3.
(CH2)6
H O
O
N C (CH2)4 C
(a)
Write the structural formula of the two monomers of nylon 6.6.
(2 marks)
(b)
Name the type of polymerization involved in making nylon.
(1 mark)
A student used the following set-up to prepare a compound W.
long glass tube
water
5 cm3 propan-1-ol
+ 5 cm3 potassium dichromate solution
+ 5 drops of acid Y + pumice stones
heat
(a)
Give the systematic name of compound W.
(b)
Why water bath, instead of a naked flame is used for heating the test tube and its contents? (1 mark)
(c)
Suggest what Y is. State its function in the reaction.
(2 marks)
(d)
Explain the function of the long glass tube.
(2 marks)
(e)
Write an equation for the reaction occurring in the experiment.
(1 mark)
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(1 mark)
3
4. A 2.0g impure sample of potassium carbonate was dissolved in deionized water and diluted to 250.0cm3.
25.0cm3 of the diluted solution required 24.5cm3 of 0.10M hydrochloric acid for complete reaction.
Calculate the purity (percentage by mass) of the potassium carbonate in the sample.
(5 marks)
(Relative atomic mass: C = 12, O = 16, K = 39)
5. Silvery metal P reacts vigorously with water to form colourless solution Q. When Q is subject to the flame test,
it gives a lilac flame. When Q is added to copper(II) nitrate solution, precipitate R is formed. R changes into
black solid S upon strong heating.
(a)
What is metal P? Write a balanced equation for the reaction between P and water.
(1 mark)
(b)
Describe how the flame test on Q can be carried out in the laboratory.
(2 marks)
(c)
Write an ionic equation for the formation of R.
(1 mark)
(d)
Name solid S.
(1 mark)
End of paper
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2005–2006 F.5 Chemistry Test 7
25/1/2006
(Time allowed: 40 minutes)
Name: ______________________ ( )
F5 ( )
Mark:__________________
Section A: Multiple Choice (10%)
1
2
3
4
5
6
7
8
9
10
A
B
C
D
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