ICSE Chemistry Past Year Paper with Solutions - 2023 | Chemistry Class 10 ICSE PDF Download

 Page 1


S o l u t i o n f o r C H E M I S T R Y
( S C I E N C E P A P E R - 2 )
______________________________________________________________________
______
Maximum Marks: 80
T ime allowed T wo hours
Answers to this Paper must be written on the paper provided separately
Y ou will not be allowed to write during first 15 minutes.
This time is to be spent in reading the question paper .
The time given at the head of this Paper is the time allowed for writing the answers.
______________________________________________________________________
______
Section A is compulsory . Attempt any four questions from Section B.
The intended marks for questions or parts of questions are given in brackets [ ].
______________________________________________________________________
______
SECTION A (40 Marks)
(Attempt all questions from this Section. )
Question 1
Choose the correct answers to the questions from the given options. [15]
(Do not copy the questions, write the correct answers only .)
(i) An element in period 3, whose electron af finity is zero:
(a) Neon
(b) Sulphur
(c) Sodium
(d) Argon
Answer: (d)
Argon belongs to period 3. It is an inert element and stable. It neither requires gain nor
loss. It has its octet complete and hence it has the zero electron af finity .
(ii) An element with the largest atomic radius among the following is:
(a) Carbon
(b) Nitrogen
Page 2


S o l u t i o n f o r C H E M I S T R Y
( S C I E N C E P A P E R - 2 )
______________________________________________________________________
______
Maximum Marks: 80
T ime allowed T wo hours
Answers to this Paper must be written on the paper provided separately
Y ou will not be allowed to write during first 15 minutes.
This time is to be spent in reading the question paper .
The time given at the head of this Paper is the time allowed for writing the answers.
______________________________________________________________________
______
Section A is compulsory . Attempt any four questions from Section B.
The intended marks for questions or parts of questions are given in brackets [ ].
______________________________________________________________________
______
SECTION A (40 Marks)
(Attempt all questions from this Section. )
Question 1
Choose the correct answers to the questions from the given options. [15]
(Do not copy the questions, write the correct answers only .)
(i) An element in period 3, whose electron af finity is zero:
(a) Neon
(b) Sulphur
(c) Sodium
(d) Argon
Answer: (d)
Argon belongs to period 3. It is an inert element and stable. It neither requires gain nor
loss. It has its octet complete and hence it has the zero electron af finity .
(ii) An element with the largest atomic radius among the following is:
(a) Carbon
(b) Nitrogen
(c) Lithium
(d) Beryllium
Answer: (c)
For the elements belonging to one period, an increase in atomic number results in
decrease in atomic radius. Therefore, the ef fective nuclear charge increases along a
period and results in decreasing atomic radii.
So Li has the largest atomic radius.
(iii) The compound that is not an ore of aluminium:
(a) Cryolite
(b) Corundum
(c) Fluorspar
(d) Bauxite
Answer: (c)
Fluorspar is calcium fluoride having a chemical formula as CaF
2
.
Bauxite - Al
2
O
3
.2H
2
O
It is the main source of aluminium. It is composed of mainly aluminium-bearing
minerals.
Corundum - Al
2
O
3
It is an aluminium oxide. It occurs as a crystal in many colors. Along with aluminium, it
contains traces of iron, titanium, vanadium and chromium.
Cryolite - Na
3
AlF
6
It is a very rare aluminium halide mineral, which occurs as a colourless to white crystal.
(iv) The vapour density of CH
3
OH is (At. Wt. C-12, H=1, 0=16)
(a) 32
(b) 18
(c) 16
(d) 34
Answer: (c)
Page 3


S o l u t i o n f o r C H E M I S T R Y
( S C I E N C E P A P E R - 2 )
______________________________________________________________________
______
Maximum Marks: 80
T ime allowed T wo hours
Answers to this Paper must be written on the paper provided separately
Y ou will not be allowed to write during first 15 minutes.
This time is to be spent in reading the question paper .
The time given at the head of this Paper is the time allowed for writing the answers.
______________________________________________________________________
______
Section A is compulsory . Attempt any four questions from Section B.
The intended marks for questions or parts of questions are given in brackets [ ].
______________________________________________________________________
______
SECTION A (40 Marks)
(Attempt all questions from this Section. )
Question 1
Choose the correct answers to the questions from the given options. [15]
(Do not copy the questions, write the correct answers only .)
(i) An element in period 3, whose electron af finity is zero:
(a) Neon
(b) Sulphur
(c) Sodium
(d) Argon
Answer: (d)
Argon belongs to period 3. It is an inert element and stable. It neither requires gain nor
loss. It has its octet complete and hence it has the zero electron af finity .
(ii) An element with the largest atomic radius among the following is:
(a) Carbon
(b) Nitrogen
(c) Lithium
(d) Beryllium
Answer: (c)
For the elements belonging to one period, an increase in atomic number results in
decrease in atomic radius. Therefore, the ef fective nuclear charge increases along a
period and results in decreasing atomic radii.
So Li has the largest atomic radius.
(iii) The compound that is not an ore of aluminium:
(a) Cryolite
(b) Corundum
(c) Fluorspar
(d) Bauxite
Answer: (c)
Fluorspar is calcium fluoride having a chemical formula as CaF
2
.
Bauxite - Al
2
O
3
.2H
2
O
It is the main source of aluminium. It is composed of mainly aluminium-bearing
minerals.
Corundum - Al
2
O
3
It is an aluminium oxide. It occurs as a crystal in many colors. Along with aluminium, it
contains traces of iron, titanium, vanadium and chromium.
Cryolite - Na
3
AlF
6
It is a very rare aluminium halide mineral, which occurs as a colourless to white crystal.
(iv) The vapour density of CH
3
OH is (At. Wt. C-12, H=1, 0=16)
(a) 32
(b) 18
(c) 16
(d) 34
Answer: (c)
Molecular mass of methyl alcohol = (1 12 + 3 1 + 16 1 + 1 1) = 32 × × × ×
V apour density = = = 16
?????????????????? ???????? 2
32
2
(v) Which of the following reactions takes place at the anode during the electroplating of
an article with silver?
(a) Ag-1e ? Ag
1 +
(b) Ag+1e ? Ag¹-
(c) Ag-1e? Ag
(d) None of the above
Answer: (a)
In electroplating with silver , oxidation reaction at anode takes place:
Ag - 1e
-
? Ag
1 +
(vi) The metallic hydroxide which forms a deep inky blue solution with excess
ammonium hydroxide solution is:
(a) Fe(OH)
2
(b) Cu(OH)
2
(c) Ca(OH)
2
(d) Fe(OH)
3
Answer: (b)
Copper (II) hydroxide reacts with a solution of excess ammonia to form a deep blue
solution of tetraamine copper complex ions. In the presence of oxygen it acts as a
catalyst for oxidation of ammonia. It results in forming copper ammine nitrites.
The reaction can be given as,
Cu(OH)
2
+ 4NH
4
OH ? [Cu(NH
3
)
4
](OH)
2
+ 4H
2
O ? Cu(NO
2
)
2
(NH
3
)
(vii) An example of a cyclic organic compound is:
(a) Propene
(b) Pentene
(c) Butene
(d) Benzene
Page 4


S o l u t i o n f o r C H E M I S T R Y
( S C I E N C E P A P E R - 2 )
______________________________________________________________________
______
Maximum Marks: 80
T ime allowed T wo hours
Answers to this Paper must be written on the paper provided separately
Y ou will not be allowed to write during first 15 minutes.
This time is to be spent in reading the question paper .
The time given at the head of this Paper is the time allowed for writing the answers.
______________________________________________________________________
______
Section A is compulsory . Attempt any four questions from Section B.
The intended marks for questions or parts of questions are given in brackets [ ].
______________________________________________________________________
______
SECTION A (40 Marks)
(Attempt all questions from this Section. )
Question 1
Choose the correct answers to the questions from the given options. [15]
(Do not copy the questions, write the correct answers only .)
(i) An element in period 3, whose electron af finity is zero:
(a) Neon
(b) Sulphur
(c) Sodium
(d) Argon
Answer: (d)
Argon belongs to period 3. It is an inert element and stable. It neither requires gain nor
loss. It has its octet complete and hence it has the zero electron af finity .
(ii) An element with the largest atomic radius among the following is:
(a) Carbon
(b) Nitrogen
(c) Lithium
(d) Beryllium
Answer: (c)
For the elements belonging to one period, an increase in atomic number results in
decrease in atomic radius. Therefore, the ef fective nuclear charge increases along a
period and results in decreasing atomic radii.
So Li has the largest atomic radius.
(iii) The compound that is not an ore of aluminium:
(a) Cryolite
(b) Corundum
(c) Fluorspar
(d) Bauxite
Answer: (c)
Fluorspar is calcium fluoride having a chemical formula as CaF
2
.
Bauxite - Al
2
O
3
.2H
2
O
It is the main source of aluminium. It is composed of mainly aluminium-bearing
minerals.
Corundum - Al
2
O
3
It is an aluminium oxide. It occurs as a crystal in many colors. Along with aluminium, it
contains traces of iron, titanium, vanadium and chromium.
Cryolite - Na
3
AlF
6
It is a very rare aluminium halide mineral, which occurs as a colourless to white crystal.
(iv) The vapour density of CH
3
OH is (At. Wt. C-12, H=1, 0=16)
(a) 32
(b) 18
(c) 16
(d) 34
Answer: (c)
Molecular mass of methyl alcohol = (1 12 + 3 1 + 16 1 + 1 1) = 32 × × × ×
V apour density = = = 16
?????????????????? ???????? 2
32
2
(v) Which of the following reactions takes place at the anode during the electroplating of
an article with silver?
(a) Ag-1e ? Ag
1 +
(b) Ag+1e ? Ag¹-
(c) Ag-1e? Ag
(d) None of the above
Answer: (a)
In electroplating with silver , oxidation reaction at anode takes place:
Ag - 1e
-
? Ag
1 +
(vi) The metallic hydroxide which forms a deep inky blue solution with excess
ammonium hydroxide solution is:
(a) Fe(OH)
2
(b) Cu(OH)
2
(c) Ca(OH)
2
(d) Fe(OH)
3
Answer: (b)
Copper (II) hydroxide reacts with a solution of excess ammonia to form a deep blue
solution of tetraamine copper complex ions. In the presence of oxygen it acts as a
catalyst for oxidation of ammonia. It results in forming copper ammine nitrites.
The reaction can be given as,
Cu(OH)
2
+ 4NH
4
OH ? [Cu(NH
3
)
4
](OH)
2
+ 4H
2
O ? Cu(NO
2
)
2
(NH
3
)
(vii) An example of a cyclic organic compound is:
(a) Propene
(b) Pentene
(c) Butene
(d) Benzene
Answer: (d)
From these four options, we can infer that a cyclic unsaturated carbon compound would
have ring structure with at least one double or triple bond between the carbon atoms.
One such compound is benzene. In benzene, six carbon atoms form a ring structure
and there are three single and three double bonds between the carbon atoms. Hence,
benzene can be taken as an example of a cyclic unsaturated carbon compound.
(viii) In the laboratory preparation, HCI gas is dried by passing through:
(a) dilute nitric acid
(b) concentrated sulphuric acid
(c) dilute sulphuric acid
(d) acidified water
Answer: (b)
The hydrogen chloride gas is passed through concentrated sulphuric acid to remove the
moisture present in the gas. Due to its hygroscopic nature, concentrated sulphuric acid
absorbs moisture from the air , dilutes, and acts as a drying agent. It has a high af finity
for water , so it absorbs it quickly .
Thus, sulphuric acid acts as a dehydrating agent.
(ix) The nitrate which on thermal decomposition leaves behind a residue which is yellow
when hot and white when cold:
(a) Lead nitrate
(b) Ammonium nitrate
(c) Copper nitrate.
(d) Zinc nitrate
Answer: (d)
Zinc nitrate is a colourless crystalline solid with the chemical formula Zn(NO
3
)
2
When Zinc nitrate decomposes, it produces zinc oxide, a yellow-colored oxide of zinc
when hot and white when cold.
Zn(NO
3
)
2
(s) ? ZnO (s) + 2NO
2
(g) + O
2
(g)
Page 5


S o l u t i o n f o r C H E M I S T R Y
( S C I E N C E P A P E R - 2 )
______________________________________________________________________
______
Maximum Marks: 80
T ime allowed T wo hours
Answers to this Paper must be written on the paper provided separately
Y ou will not be allowed to write during first 15 minutes.
This time is to be spent in reading the question paper .
The time given at the head of this Paper is the time allowed for writing the answers.
______________________________________________________________________
______
Section A is compulsory . Attempt any four questions from Section B.
The intended marks for questions or parts of questions are given in brackets [ ].
______________________________________________________________________
______
SECTION A (40 Marks)
(Attempt all questions from this Section. )
Question 1
Choose the correct answers to the questions from the given options. [15]
(Do not copy the questions, write the correct answers only .)
(i) An element in period 3, whose electron af finity is zero:
(a) Neon
(b) Sulphur
(c) Sodium
(d) Argon
Answer: (d)
Argon belongs to period 3. It is an inert element and stable. It neither requires gain nor
loss. It has its octet complete and hence it has the zero electron af finity .
(ii) An element with the largest atomic radius among the following is:
(a) Carbon
(b) Nitrogen
(c) Lithium
(d) Beryllium
Answer: (c)
For the elements belonging to one period, an increase in atomic number results in
decrease in atomic radius. Therefore, the ef fective nuclear charge increases along a
period and results in decreasing atomic radii.
So Li has the largest atomic radius.
(iii) The compound that is not an ore of aluminium:
(a) Cryolite
(b) Corundum
(c) Fluorspar
(d) Bauxite
Answer: (c)
Fluorspar is calcium fluoride having a chemical formula as CaF
2
.
Bauxite - Al
2
O
3
.2H
2
O
It is the main source of aluminium. It is composed of mainly aluminium-bearing
minerals.
Corundum - Al
2
O
3
It is an aluminium oxide. It occurs as a crystal in many colors. Along with aluminium, it
contains traces of iron, titanium, vanadium and chromium.
Cryolite - Na
3
AlF
6
It is a very rare aluminium halide mineral, which occurs as a colourless to white crystal.
(iv) The vapour density of CH
3
OH is (At. Wt. C-12, H=1, 0=16)
(a) 32
(b) 18
(c) 16
(d) 34
Answer: (c)
Molecular mass of methyl alcohol = (1 12 + 3 1 + 16 1 + 1 1) = 32 × × × ×
V apour density = = = 16
?????????????????? ???????? 2
32
2
(v) Which of the following reactions takes place at the anode during the electroplating of
an article with silver?
(a) Ag-1e ? Ag
1 +
(b) Ag+1e ? Ag¹-
(c) Ag-1e? Ag
(d) None of the above
Answer: (a)
In electroplating with silver , oxidation reaction at anode takes place:
Ag - 1e
-
? Ag
1 +
(vi) The metallic hydroxide which forms a deep inky blue solution with excess
ammonium hydroxide solution is:
(a) Fe(OH)
2
(b) Cu(OH)
2
(c) Ca(OH)
2
(d) Fe(OH)
3
Answer: (b)
Copper (II) hydroxide reacts with a solution of excess ammonia to form a deep blue
solution of tetraamine copper complex ions. In the presence of oxygen it acts as a
catalyst for oxidation of ammonia. It results in forming copper ammine nitrites.
The reaction can be given as,
Cu(OH)
2
+ 4NH
4
OH ? [Cu(NH
3
)
4
](OH)
2
+ 4H
2
O ? Cu(NO
2
)
2
(NH
3
)
(vii) An example of a cyclic organic compound is:
(a) Propene
(b) Pentene
(c) Butene
(d) Benzene
Answer: (d)
From these four options, we can infer that a cyclic unsaturated carbon compound would
have ring structure with at least one double or triple bond between the carbon atoms.
One such compound is benzene. In benzene, six carbon atoms form a ring structure
and there are three single and three double bonds between the carbon atoms. Hence,
benzene can be taken as an example of a cyclic unsaturated carbon compound.
(viii) In the laboratory preparation, HCI gas is dried by passing through:
(a) dilute nitric acid
(b) concentrated sulphuric acid
(c) dilute sulphuric acid
(d) acidified water
Answer: (b)
The hydrogen chloride gas is passed through concentrated sulphuric acid to remove the
moisture present in the gas. Due to its hygroscopic nature, concentrated sulphuric acid
absorbs moisture from the air , dilutes, and acts as a drying agent. It has a high af finity
for water , so it absorbs it quickly .
Thus, sulphuric acid acts as a dehydrating agent.
(ix) The nitrate which on thermal decomposition leaves behind a residue which is yellow
when hot and white when cold:
(a) Lead nitrate
(b) Ammonium nitrate
(c) Copper nitrate.
(d) Zinc nitrate
Answer: (d)
Zinc nitrate is a colourless crystalline solid with the chemical formula Zn(NO
3
)
2
When Zinc nitrate decomposes, it produces zinc oxide, a yellow-colored oxide of zinc
when hot and white when cold.
Zn(NO
3
)
2
(s) ? ZnO (s) + 2NO
2
(g) + O
2
(g)
(x) The salt formed when concentrated sulphuric acid reacts with KNO
3
above 200°C:
(a) K
2
SO
4
(b) K
2
SO
3
(c) KHSO
4
(d) KHSO
3
Answer: (a)
When concentrated sulphuric acid reacts with KNO
3
above 200°C K
2
SO
4
is formed.
KNO
3
+ H
2
SO
4
? KHSO
4
+ HNO
3
( Below 200
0
C )
KNO
3
+ H
2
SO
4
? K
2
SO
4
+ HNO
3
( Above 200
0
C )
(xi)
The property exhibited by concentrated sulphuric acid when it is used to prepare
hydrogen chloride gas from potassium chloride:
(a) Dehydrating property
(b) Drying property
(c) Oxidizing property
(d) Non-volatile acid property
Answer: (d)
Concentrated sulphuric acid has a high boiling point (338
0
C) and so, it is considered to
be a non-volatile acid. It is therefore used for preparing volatile acids like hydrochloric
acid, nitric acid and acetic acid from their salts by double decomposition.
(xii)
The hydrocarbon formed when sodium propanoate and soda lime are heated together:
(a) Methane
(b) Ethane
(c) Ethene
(d) Propane
Answer: (b)