ICSE CHEMISTRY CLASS 10 PRACTICE PAPER-3
SUPLHURIC ACID, NITRIC ACID, SALTS, METALLURGY, EMPIRICAL FORMULA and PRACTICAL CHEMISTRY
Section I (40
Marks)
Answer all the
questions
Question 1
a) Choose the correct answers from the
words given below 5M
(calcination, NaOH, Magnetic separation,
Al(OH)3, Zinc, Roasting, Aqua regia)
i)
The suitable method for concentration of
Iron ore.
ii) Conversion
of sulphides into metal oxides in presence of air.
iii) The
chemical used to remove impurities from Bauxite ore in Baeyer’s process.
iv) Distillation
refining is suitable for the refining of this metal.
v) A
mixture of 3 vol. of Conc. HCl and 1 vol. of Conc.HNO3 .
b)
Match the following. Example- vi-A 5M
Part-A
i) A
simple whole number ratio
ii)
The metal used in thermite welding
iii)
An insoluble salt
iv)
The process of heating concentrated
ore
in the absence of air.
v)
An insoluble base
vi)
A strong acid
Part-B
A)
Hydrochloric acid
B)
AgCl
C)
Empirical formula
D)
Al(OH)3
E)
Aluminium
F)
Roasting
G)
Calcination
c) Select the correct answers from the
words given below: 10M
i)
The metal which is a poor conductor of
electricity:
A)
Copper B) Aluminium C) Gold D) Tungsten
ii)
Which of the following acts as a strong
oxidizing agent
A)
Conc. HNO3 B) dil.H2SO4
C) dil.HCl D) NaOH soln.
iii) The
acidity of Sodium hydroxide is
A)
1 B) 2 C) 3 D) 4
iv) Which
of the following is not an acid salt:
A)
NaHCO3 B) NaHSO4 C) Na2SO4 D) NaHSO3
v)
The water of crystallization in hydrated
Copper sulphate:
A)
4 B) 5 C) 6 D) 7
vi) A
volatile salt
A)
FeCl3 B)
FeCl2 C)
CuSO4 D) NaCl
vii) A
complex salt
A)
Iron(III) sulphate B) Iron(II)
sulphate
C)
Tetra amine copper sulphate D)
Copper(II) sulphate
viii) An
alkali metal belongs to period 3 in the periodic table.
A)
Na B) Mg C) Ca D) Al
ix) The
composition of solder:
A)
Pb+Cu B) Pb+Sn C) Pd+Sn D) Zn+Cu
x)
The metal used to galvanize Iron
articles.
A)
Copper B) Zinc C) Silver D) Mercury
d) Fill in the blanks:- 5M
i)
____________(sulphide/carbonate) ores
are concentrated by froth floatation method.
ii) Haematite
is an ore of ____________(Aluminium/Iron).
iii) Nitric
acid on heating liberates ______________(NO2/NO).
iv) _____________
(Hydrochloric/Sulphuric) acid is used in pickling of metals.
v) FeCl3
is a ___________ (deliquescent/hygroscopic) substance.
e) Calculate the molecular weights of
the following compounds.
(H-1, C-12, N-14, O-16, S-32, K-39,
Cr-52, Cu-64) 3M
i)
Sodium hydroxide
ii) Potassium
dichromate
iii) Copper
sulphate
Find
the empirical formula of the
following compounds. 2M
iv) Glucose
v) Ethane
f)
Name the following. 5M
i)
The non metal which is used in alloying.
ii)
The rocky impurities associated with an orre.
iii)
A monobasic weak acid.
iv)
A strong acid which is drying agent as well as dehydrating agent.
v)
An alloy of Copper and Zinc only.
g)
Give reason why: 3M
i)
Alkali metals are highly
electropositive.
ii) Zinc
container is used as cathode in dry cells.
iii) Aluminium
is used in packaging.
Complete
and balance the following equations: 2M
iv) dil.
HCl + Mg à
v) FeSO4
+ NaOH à
Section
II (40 Marks)
Answer
any four of the following questions
Question 2 3+3+4
a) Identify
the role played by Conc. Sulphuric acid in the following reactions:
i)
3S + 2H2SO4 à
3SO2 + 2H2O
ii) CuSO4
.5H2O
CuSO4 +5H2O
iii) C12H22O11
12C + 11H2O
b) State
your observations seen when:
i)
Conc. Sulphuric acid is added to Sugar
crystals.
ii) Dil.
Suplhuric acid is added to Barium chloride solution.
iii) Conc.
H2SO4 is added to blue copper sulphate.
c) i)
Name the gas released when Sulphur is treated with Conc. Sulphuric acid.
ii) Write balanced equation for the conversion of SO2
to SO3 in Contact process with conditions if any.
Give balanced equations for the reactions :
iii) dil.H2SO4 reacts with ZnO
iv)
Copper to Copper sulphate using Conc. Sulphuric acid.
Question 3 3+3+2+2
a) i)
Name the reactants used in the preparation of HNO3 in the laboratory
method.
ii)
Give balanced equation for the above
preparation and mention the conditions
required.
iii)
Mention any one precaution to be taken during above process.
b) Give
reason why :
i) The temperature should be maintained below 2000C
in the above process.
ii) Entire apparatus is made of Glass
iii) HNO3 prepared in the laboratory
appears yellowish brown.
c) Give
balanced equations for:
i) Reaction between Coc.HNO3 and Carbon
ii) Decomposition of HNO3 on heating.
d) State
the observations seen when Conc. HNO3 is heated with
i) Pb(NO3)2 ii) Cu(NO3)2
Question 4 4+4+2
a) Give
reason:
i) In metallurgy, the
ores are converted to metal oxides.
ii) Aluminium oxide is
reduced by electrolysis but not using reducing agents.
iii) Aluminium powder
is used in paints.
iv) Zinc is used in the
alloys like Bronze and Brass.
b) i)
State the conditions required for rusting of Iron.
ii) The substance added to the ore to get rid of
impuries is called Matrix/Flux.
iii) In thermite welding Aluminium acts as a/an reducing/oxidizing agent.
iv) Metals lose/gain
electrons and form cations.
c) Give
balanced equations for the thermal decomposition of :
i)
Lead(II) carbonate ii)
Capper (II) carbonate
Question
5 3+3+4
Answer
the following questions regarding the extraction of Aluminium from Bauxite ore.
a)
i) State the formula of Bauxite ore.
ii)
Which property of Bauxite makes it react with Sodium hydroxide.
iii)The
process adding Aluminium hydroxide crystals to dil. Sodium aluminate to
precipitate out Al(OH)3 is called seeding/smelting.
b)
i) Mention any one difficulty faced during the electrolysis of Alumina.
ii)
State the composition of the electrolyte taken the Hall Heroult’s process.
iii)
Give one advantage of adding Cryolite to alumina in the above process.
c)
i)Give reason why Graphite electrodes are replaced continuously in this
process.
ii)
What are the precautions to be taken to prevent the heat loss during the
process.
iii)
Give balanced equation for the electrolytic reaction that takes place at
cathode.
iv)
Name the products formed at anode other than Oxygen.
Question
6 4+2+4
a) i)Calculate
the percentage of water in Hydrated Copper sulphate.(H-1,
O-16, S-32, Cu-64)
ii)
Determine the molecular formula of a compound having percentage composition
C-40%,
O-53.3% and H-6.7% and molecular weight is 60.
iii)
200cc of CO is ignited in presence of 150cc of Oxygen. Then find the volume of
Oxygen
that remains unused.
b) Give
balanced equations for the following conversion.
Fe
à
FeCl3 à Fe(OH)3
c) A
set of salts are treated with small amounts of Ammoinium hydroxide then
complete the following table.
Cation present in the salt
|
Observation
|
(i)
|
Pale blue ppt.
|
Fe3+
|
(ii)
|
Fe2+
|
(iii)
|
(iv)
|
Does not form a ppt.
|
Question
7 3+3+2+2
a)
Give balanced equations for the following conversions:
i)
Conc. HNO3 à H2SO4
ii)
Conc. H2SO4 à HCl
iii)
CuO à
CuSO4
b)
i) Calculate the percentage of Hydrogen in Sodium hydroxide
ii)
Find the molecular weight of the compound whose empirical formula is CH2O
and n=2
iii)
2NO + O2 à 2NO2. If all volumes are
measured at the same temperature and pressure(STP) then calculate the volume of
Oxygen required to produce 20cc of NO2.
c)
Identify the insoluble salts in the following reactions.
i)
Pb(NO3)2 + 2NaCl à 2NaNO3
+ PbCl2
ii)
ZnSO4 + (NH4)2CO3 à
ZnCO3 + (NH4)2SO4
d)
Name the acids used to produce the following salts:
i) NaCl ii)
CaSO4
(OR)
a) i)
Metals are good/poor conductors of
electricity. 3+4+3
ii) Non metals are electropositive/electropositive in nature.
iii) Sodium is a soft/hard
metal.
b) Give
one use of each of the following:
i) Solder ii) Bronze iii) Duralumin iv) Aluminium
c) Write the empirical
formulas of the following compounds:
i) C4H10 ii) C2H4O2 iii) Na2S2O8
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