Download Assertion-reason question

Assertion-reason question
Directions: Please refer to the following instructions:
A
C
D
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 while the 2nd statement is true.
Both statements are false.
1
1st statement
Coal is a major source of alkanes.
2nd statement
Coal is formed from dead marine
organisms.
2
Coal is non-renewable.
Once used, coal cannot be replenished
after a short time.
3
Coal causes serious pollution problems
when burnt in air.
Coal is a kind of fossil fuels.
4
Fossil fuels are either liquids or gases.
Petroleum and natural gas are fossil
fuels.
5
Destructive distillation is an important
process in petroleum refining.
By destructive distillation, petroleum
can be separated into various fractions
for different uses.
6
Fractional distillation of petroleum is a
chemical process.
Pure substances can be obtained from
fractional distillation of petroleum.
7
High boiling fractions from fractional
distillation of crude oil are easier to burn
that low boiling ones.
High boiling fractions burn with a
sootier flame than low boiling ones.
8
During the fractional distillation of
petroleum, fuel oil and lubricating oil
are turned into petrol.
The supply of fuel oil and lubricating oil
is greater than demand.
B
9
Liquefied petroleum gas (LPG) consists
mainly of methane.
Methane exists as a gas at room
temperature and pressure.
10 Liquefied petroleum gas is a cleaner
fuel than diesel oil.
Liquefied petroleum gas burns more
completely than diesel oil.
11 Kerosene is commonly used as a fuel for
aircrafts.
Alkane C11H24 is one of the components
of kerosene.
12 Naphtha exists as a liquid at room
Atoms in naphtha molecules are held by
temperature and pressure.
13 Bitumen obtained in the fractional
distillation of petroleum is useless.
covalent bonds.
Bitumen burns with a sootier flame than
petrol.
14 Ethene is the second member of the
alkene series.
The structural formula of ethene is
C2H4.
15 Ethane and butane have similar
chemical properties.
Ethane and butane are in the same
homologous series.
16 Ethene and propene have the same
physical properties.
Ethene and propene are in the same
homologous series.
17 The boiling point of propane is higher
than that of ethane.
The intermolecular forces between
alkane molecules increase as the number
of carbon atoms in the molecules
increases.
18 The physical properties of different
members in the same homologous series
are the same.
Members of the same homologous
series have the same functional group.
19 Methane, ethane and propane are in the
same homologous series.
They are all gases at room temperature
and pressure.
20 Butane and 2-methylpropane have the
Butane and 2-methylpropane are
same molar volume at room temperature
members of the same homologous
and pressure.
series.
21 When a mixture of butane and bromine
vapour is exposed to diffused sunlight,
the colour of the mixture fades.
Butane and bromine undergo
substitution reaction under suitable
conditions.
22 C2H5OH and CH3COOH have different
boiling points.
C2H5OH and CH3COOH have different
functional groups.
23 In a homologous series, the
In a homologous series, the successive
flammability of compounds increases as
the number of carbon atoms in the
molecules increases.
members differ from each other by a
−CH2− unit.
24 Octane (C8H8) burns with a sootier
flame than pentane (C5H12).
Octane is more viscous than pentane.
25 Propane burns with a sootier flame than
pentane (C5H12).
Each propene molecule contains one
carbon-carbon double bond.
26 Ethyne (HCCH) burns with a sootier
flame than ethane.
Both ethyne and ethene are saturated
hydrocarbons.
27 Propene is more flammable than
but-1-ene.
Propene and but-1-ene have different
physical properties.
28 Both but-1-ene and but-2-ene can
decolourize acidified potassium
permanganate solution.
Both but-1-ene and but-2-ene have the
same molecular formula.
29 Propene gives carbon monoxide when it
undergoes incomplete combustion.
Propene is an unsaturated hydrocarbon.
30 Ethane reacts with chlorine in the
presence of diffused sunlight to give
1,1,1-trichloroethane as the only
product.
Ethane is a very reactive compound.
31 Tetrabromoethane is an organic
compound.
Tetrabromoethane contains carbon.
32 Tetrachloromethane is toxic.
Chlorine is toxic.
33 Cracking of medicinal paraffin produces
unsaturated hydrocarbons.
Unsaturated hydrocarbons contain
carbon-carbon multiple bonds.
34 Cracking is an important industrial
process.
Cracking produces alkenes which are
used to produce many useful products.
35 Cracking is an exothermic process.
Heat is releases during cracking.
36 Carbon monoxide can be obtained from
cracking of heavy oil fraction.
During cracking, heavy oil fractions are
heated in the presence of air to a high
temperature.
37 Both methane and ethene are gases at
room temperature and pressure.
Both methane and ethene are covalent
compounds.
38 Some alkenes are very soluble in water.
Both water and alkenes have simple
molecular structures.
39 Propene is more reactive than propane.
Propene contains carbon-carbon double
bonds.
40 Propane is more reactive than propene.
Propane can react with chlorine in the
presence of diffused sunlight while
propene cannot.
41 Propane and propene can be
distinguished by treating with acidified
potassium dichromate solution.
Propene turns acidified potassium
dichromate solution from orange to
green whereas propane does not.
42 Propane and propene can be
distinguished by treating with acidified
potassium permanganate solution.
Propene decolourizes acidified
potassium permanganate solution
whereas propane does not.
43 Alkenes are the only hydrocarbons
which can decolourize bromine
dissolved in an organic solvent readily
in the absence of light.
The reactions between alkenes and
bromine are addition reactions.
44 All alkanes are used as fuels.
Burning alkanes is an exothermic
reaction.
45 Under any circumstances, hydrocarbons
burn in air to give carbon dioxide and
Hydrocarbons contain carbon and
hydrogen only.
water only.
46 Alkanes burn in insufficient supply of
air to form water and carbon monoxide
only.
Alkanes contain carbon and hydrogen
only.
47 H for an exothermic reaction has a
positive sign.
In an exothermic reaction, energy is
absorbed from the surroundings.
48 Liquefied petroleum gas is seldom used
Town gas is less toxic than liquefied
nowadays when compared with town
gas.
petroleum gas.
49 The major component of town gas is
methane.
Methane can be obtained by fractional
distillation of naphtha.
50 Hong Kong Town Gas is made from
petroleum.
Petroleum is a fossil fuel.
51 Carbon monoxide is a toxic gas.
Carbon monoxide reduces the oxygen
carrying capacity of blood.
52 Liquefied petroleum gas (LPG) should
only be used in a well-ventilated room.
The main components of LPG are
propane and butane.
53 If one suspects there is a leakage of
town gas, he/ she should open all the
Town gas is toxic and explosive.
windows.
54 If one suspects there is a leakage of
town gas, he/ she should turn off all the
electrical appliances in his/ her home.
An electric spark may ignite the town
gas and lead to an explosion.
55 Sulphur dioxide causes acid rain.
Sulphur dioxide dissolves in rain water
to give sulphurous acid.
56 Acid rain can corrode plastics.
Acid dissolves plastics readily.
57 Normal rainwater has a pH value of
about 5.7.
Carbon dioxide dissolves in rainwater to
give an acidic solution.
58 Carbon dioxide can cause acid rain.
Carbon dioxide gives carbonic acid
when dissolved in water.
59 During thunderstorm, the rainwater is
more acidic than normal water.
Nitrogen dioxide is formed in lightning
and it dissolves in rainwater to give an
acidic solution.
60 Methane is a greenhouse gas.
Methane can be produced from the
decay of organic waste.
61 Global warming results from the
increasing use of fossil fuels.
Carbon dioxide given off in the burning
of fossil fuels traps the solar energy
which is re-radiated from the Earth’s
surface to the atmosphere.
62 Water vapour produced from the
Water vapour is a greenhouse gas.
combustion of fossil fuels enhances
greenhouse effect.
63 Global warming causes the rise of sea
levels.
Global warming may cause huge
increase of rainfall in certain regions.
64 Catalytic converters can only be
installed in cars using unleaded petrol.
Lead compounds can poison the
catalysts in catalytic converters.
65 Scrubblers installed in motor cars can
reduce acid rain problems.
Sulphur dioxide given off from the
burning of fuels can be removed by
scrubbers.
66 Catalytic converters installed in cars can
reduce air pollution problems.
Oxides of nitrogen and carbon
monoxide given off from the burning of
fuels can be removed by catalytic
converters.
67 Nowadays, fossil fuels are the major
Fossil fuels are convenient to use and
energy sources.
68 Hydroelectric power is very suitable for
Hong Kong.
relatively cheap.
Hydroelectric power is a renewable
energy source.
69 Geothermal energy is non-polluting.
Geothermal wells do not release any
toxic gases.
70 Geothermal energy is a widely used
energy source.
There is permanent supply of heat from
underground.
71 Methane is a component of biogas fuel.
Methane is a clean fuel.
72 Nuclear energy is a non-renewable
energy source.
Nuclear energy is a cleaner energy
source when compared with fossil fuels.
73 Nuclear energy is a non-renewable
energy.
Nuclear energy is produced from the
nuclear fission of uranium nuclei.
74 Aqueous ethanol can turn moist pH
paper red.
Ethanol dissolves in water to give
hydrogen ions.
75 Ethanol is a good conductor of
electricity.
Ethanol is miscible with water.
76 Ethanol can be used as a fuel.
Energy is produced when ethanol is
burnt.
77 Methylated spirit is a common fuel.
Methylated spirit contains methanol
which produces energy when burnt.
78 Burning gasohol causes more pollution
problems than burning petrol.
Gasohol contains many impurities while
petrol does not contain any impurities.
79 Ethanol is used as a solvent in the
preparation of iodine culture.
Both ethanol and iodine have simple
molecular structures.
80 After the fermentation of glucose
Ethanol and other compounds in the
solution, ethanol can be separated from
the reaction mixture by fractional
distillation.
reaction mixture have different boiling
points.
81 Fermentation of sucrose solution can
produce a very concentrated ethanol
solution.
The concentration of ethanol can be
increased by adding more yeast to the
sucrose solution during fermentation.
82 Ethanol produced from catalytic
hydration of ethene is mainly used to
All alcoholic beverages contain ethanol.
make alcoholic beverages.
83 Ethanol is s saturated hydrocarbon.
All atoms in an ethanol molecule are
held by single bonds.
84 The ethanol content of beer is the same
as that of white wine.
Both beer and white wine are produced
by fermentation.
85 A glass of wine turns sour upon standing
Ethanol in the wine undergoes oxidation
in air.
to give ethanoic acid.
86 If a bottle of wine is left opened for a
long time, it becomes sweet.
Ethyl ethanoate is produced by the
action of bacteria in the wine.
87 The body-alcohol level of a drunk driver
can be tested by passing his breathed air
into acidified potassium dichromate
Ethanol turns acidified potassium
permanganate solution from orange to
green.
solution.
88 Ethanol can be oxidized to ethanoic acid
in the presence of concentrated
sulphuric acid and potassium
dichromate solution.
Concentrated sulphuric acid is a strong
oxidizing agent.
89 Vinegar can be produced by refluxing
propan-1-ol with acidified potassium
dichromate solution.
Vinegar is an alkanoic acid.
90 Both ethene and ethanol can react with
acidified potassium permanganate
solution.
Ethene and ethanol belong to different
homologous series.
91 Only ethyl ethanoate is formed when
ethanoic acid reacts with alcohol.
Neutralization occurs when ethanoic
acid reacts with ethanol.
92 Esters can be used as artificial
flavourings.
Esters have sweet and fruity smells.
93 Esterification is an irreversible reaction.
Esterification is an addition reaction.
94 Esterification is a substitution reaction.
When an alkanol molecule combines
with an alkanoic acid molecule, a water
molecule is eliminated.
95 Ethyl ethanoate has a boiling point
higher than that of ethanoic acid.
Ethyl ethanoate is a covalent compound
while ethanoic acid is an ionic
compound.
96 When methyl ethanoate is heated with
dilute sodium hydroxide solution under
reflux, ethanol and sodium methanoate
are obtained.
Methyl ethanoate is an ester formed
from the reaction between ethanol and
methanoic acid.