Lab. Technique / Section 0 / Sect0pp.doc / S. W. Tse / P.1
86 Q.29
Which of the following techniques can be used to obtain ammonium chloride from a solid
mixture of ammonium chloride and sodium chloride?
A.
B.
C.
D.
chromatography
ion exchange
sublimation
filtration
87 Q.28
gas jar Y
air
glass plate
gas jar X
nitrogen dioxide (brown colour)
If the glass plate in the above diagram is removed, a brown coloration gradually appears in gas
jar Y because
A.
B.
C.
D.
nitrogen dioxide is lighter than air.
nitrogen dioxide reacts with air to form a brown compound.
molecules of both gases are in continual random motion.
weak intermolecular forces exist between air molecules and nitrogen dioxide molecules.
87 Q.30
chromatographic paper
solvent front
starting position
P
S
Q
T
R
(known pigments)
M
(mixture of pigments)
The above diagram represents the results of paper chromatography experiment. It can be
concluded that the pigments present in mixture M are
A.
B.
C.
D.
P, R and T.
P, Q and T.
P, R and another unknown pigment.
P and two other unknown pigments.
Lab. Technique / Section 0 / Sect0pp.doc / S. W. Tse / P.2
88 Q.8
Large crystals of a salt can be obtained by
A.
B.
C.
D.
adding ice to a hot, saturated solution of the salt.
allowing a hot, saturated solution of the stand overnight at room temperature.
heating a saturated solution of the salt to dryness.
cooling a hot, saturated solution of the salt under running tap water.
88 Q.30
Which of the following equations represents a dehydration reaction?
A.
B.
C.
D.
Cu + 2H2SO4 → CuSO4 + SO2 + 2H2O
(NH4)2CO3 → 2NH3 + CO2 + H2O
C2H5OH → C2H4 + H2O
CuSO4 + 5H2O → CuSO4.5H2O
88 Q.39
Which of the following hazard warning labels should be attached to a bottle of liquid bromine?
(1)
(2)
explosive
toxic
(4)
(3)
oxidizing
A.
C.
(1) and (2) only
(1), (3) and (4) only
corrosive
B.
D.
(1) and (4) only
(2), (3) and (4)
89 Q.27
Which of the following combinations would cause “striking back” in a Bunsen flame?
A.
B.
C.
D.
Air hole
fully closed
fully closed
fully open
fully open
Gas supply
too weak
too strong
too weak
too strong
Lab. Technique / Section 0 / Sect0pp.doc / S. W. Tse / P.3
90 Q.30
Which of the following methods can be used to obtain sodium chloride from a solid mixture
containing sodium chloride and ammonium chloride?
A. heating
B. adding water and filtering
C. adding sodium hydroxide solution and filtering
D. adding silver nitrate solution and filtering
90 Q.50
Silver bromides turn grey when it is
Light energy changes silver bromide to
exposed to light.
silver oxide.
1st statement 2nd statement
A.
True
True
2nd statement is a correct explanation of the 1st one.
B.
True
True
2nd statement is NOT a correct explanation of the 1st one.
C.
True/False
False/True
Only ONE of the statements is true, the other is false.
D.
False
False
----91 Q.5
Tetrachloromethane is a common solvent in the chemistry laboratory. Which of the following
hazard warning labels should be displayed on a bottle of tetrachloromethane?
(1)
(2)
(3)
toxic
corrosive
A.
C.
(1) only
(1) and (3) only
oxidizing
B.
D.
(2) only
(2) and (3) only
93 Q.42
funnel
pure solid
evaporating
basin
impure solid
heat
Which of the following solids can be purified using the above set-up?
A. potassium iodide
B. ammonium chloride
C. lead (II) bromide
D. sodium hydrogencarbonate
Lab. Technique / Section 0 / Sect0pp.doc / S. W. Tse / P.4
94 Q.32
Which of the following label(s) should be placed on a bottle containing tetrachloromethane?
toxic
(1)
A.
C.
(1) only
(1) and (3) only
(3)
corrosive
flammable
(2)
B.
D.
(2) only
(2) and (3) only
96 Q.16
Which of the following methods can be used to separated colourings in brown chocolate
beans?
A.
C.
filtration
paper chromatography
B.
D.
crystallization
fractional distillation
97 Q.10
Which of the following combinations is INCORRECT?
A.
B.
C.
D.
Chemical
calcium
potassium
ethanol
solution
Method of storage
under water
under paraffin oil
in a cool place
in a brown bottle
98 Q.26
Some physical properties of a compound X are listed below:
melting point : 82°C
boiling point .: 221°C
solubility in water : soluble
Which of the following is the most appropriate method to obtain X from a solution of X in
water ?
A.
C.
decantation
fractional distillation
B.
D.
crystallization
paper chromatography
Lab. Technique / Section 0 / Sect0pp.doc / S. W. Tse / P.5
99 Q.35 The label below is displayed on a container for chemical X:
Which of the following chemicals may X be?
(1) bromochlorodifluoromethane
(2) ethanol
(3) potassium
A.
C.
(1) only
(1) and (3) only
B.
D.
(2) only
(2) and (3) only
01 Q.2
The hazard warning label shown below is found on a compressed gas cylinder.
Which of the following gases may be contained in the cylinder?
A.
C.
hydrogen
chlorine
B.
D.
oxygen
argon
02 Q.22
Which of the following methods should be used to obtain hydrated copper(II) sulphate from
copper(II) sulphate solution?
A.
C.
crystallization
fractional distillation
B.
D.
distillation
heating under reflux
Lab. Technique / Section 0 / Sect0pp.doc / S. W. Tse / P.6
M.C. Answer
85
94
32
03
86
29
95
A
C
87
28
30
96
16
C
D
C
88
8
30
39
97
10
B
C
C
A
89
27
98
26
C
B
90
30
50
99
35
A
C
91
5
00
D
92
B
01
2
A
93
42
B
02
22
A