Class 11 Chemistry: CBSE Sample Question Papers - 1 (2024-25) | Sample Papers for Class 11 Medical and Non-Medical - JEE PDF Download

 Page 1


Time Allowed: 3 hours Maximum Marks: 70 
General Instructions:
1. There are 33 questions in this question paper with internal choice.
2. SECTION A consists of 16 multiple-choice questions carrying 1 mark each.
3. SECTION B consists of 5 very short answer questions carrying 2 marks each.
4. SECTION C consists of 7 short answer questions carrying 3 marks each.
5. SECTION D consists of 2 case-based questions carrying 4 marks each.
6. SECTION E consists of 3 long answer questions carrying 5 marks each.
7. All questions are compulsory.
8. The use of log tables and calculators is not allowed
Section A
a) 237.6°F b) -317.6°F
c) 317.6 °F d) -187.6°F
1. -122°C in Fahrenheit scale is [1]
a) 3p b) 3d
c) 3s d) 3f
2. The orbital with n = 3 and l = 2 is [1]
a) is never negative. b) may be positive or negative.
c) is always negative. d) is always positive.
3. The enthalpies of elements in their standard states are taken as zero. The enthalpy of formation of a compound
is:
[1]
a) 14 b) 32
c) 16 d) 12
4. Maximum number of electrons in a subshell with l = 3 and n = 4 is _____. [1]
a) 30.0 kJ b) 42.0 kJ
c) 34.0 kJ d) 23.0 kJ
5. To vaporize 100.0 g carbon tetrachloride at its normal boiling point, 349.9 K, and P =1 atm, 19.5 kJ of heat is
required. Calculate  for CCl
4
?
[1]
? H v a p 6. The energy associated with the first orbit in the hydrogen atom is -2.18 10
-18
 J/atom. Calculate the radius of
[1]
× Page 1 of 12
Page 2


Time Allowed: 3 hours Maximum Marks: 70 
General Instructions:
1. There are 33 questions in this question paper with internal choice.
2. SECTION A consists of 16 multiple-choice questions carrying 1 mark each.
3. SECTION B consists of 5 very short answer questions carrying 2 marks each.
4. SECTION C consists of 7 short answer questions carrying 3 marks each.
5. SECTION D consists of 2 case-based questions carrying 4 marks each.
6. SECTION E consists of 3 long answer questions carrying 5 marks each.
7. All questions are compulsory.
8. The use of log tables and calculators is not allowed
Section A
a) 237.6°F b) -317.6°F
c) 317.6 °F d) -187.6°F
1. -122°C in Fahrenheit scale is [1]
a) 3p b) 3d
c) 3s d) 3f
2. The orbital with n = 3 and l = 2 is [1]
a) is never negative. b) may be positive or negative.
c) is always negative. d) is always positive.
3. The enthalpies of elements in their standard states are taken as zero. The enthalpy of formation of a compound
is:
[1]
a) 14 b) 32
c) 16 d) 12
4. Maximum number of electrons in a subshell with l = 3 and n = 4 is _____. [1]
a) 30.0 kJ b) 42.0 kJ
c) 34.0 kJ d) 23.0 kJ
5. To vaporize 100.0 g carbon tetrachloride at its normal boiling point, 349.9 K, and P =1 atm, 19.5 kJ of heat is
required. Calculate  for CCl
4
?
[1]
? H v a p 6. The energy associated with the first orbit in the hydrogen atom is -2.18 10
-18
 J/atom. Calculate the radius of
[1]
× Page 1 of 12
a) 1.3225 nm b) 13.2250 nm
c) 2.3225 nm d) 0.13225 nm
Bohr’s fifth orbit for hydrogen atom.
a) reduction process b) All of these
c) addition process d) oxidation process
7. In the given reaction, 
CH
2
 = CH
2
(g) + H
2
(g)  CH
3
 - CH
3
(g) 
ethene undergoes 
[1]
? a) Chromatography b) Spectroscopy
c) Differential Extraction d) Distillation under reduced pressure
8. To which the terms stationary phase and mobile phase are associated? [1]
a) Ethyne b) Methane
c) Ethene d) Ethane
9. What product is obtained by heating ethylidene chloride with alcoholic KOH? [1]
a) 1.36, 1.71, 1.40 b) 1.36, 1.40, 1.71
c) 1.71, 1.40, 1.36 d) 1.71, 1.36, 1.40
10. The ionic radii of N
3-
, O
2-
 and F
-
 are respectively given by:
[1]
a) The boundaries permit the flow of matter
into it but not vice versa.
b) The boundaries permit the flow of matter
into or out of it.
c) The boundaries prevent the flow of matter
into or out of it.
d) The boundaries prevent the flow of matter
out of it but not vice versa.
11. In a closed system, which of the following take place? [1]
a) infinite b) zero
c) one d) two
12. The number of possible conformational isomers of ethane is ________. [1]
a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the
correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
13. Assertion (A): The term tautomerism was introduced by Maxwell in order to explain the chemical reactivity of
a substance according to two possible structures. 
Reason (R): Metamers can also be chain isomers or position isomers.
[1]
a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the
correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
14. Assertion (A): C
6
H
5
F gives large amount of nitration products than all the other halides. 
Reason (R): F is most electronegative.
[1]
Page 2 of 12
Page 3


Time Allowed: 3 hours Maximum Marks: 70 
General Instructions:
1. There are 33 questions in this question paper with internal choice.
2. SECTION A consists of 16 multiple-choice questions carrying 1 mark each.
3. SECTION B consists of 5 very short answer questions carrying 2 marks each.
4. SECTION C consists of 7 short answer questions carrying 3 marks each.
5. SECTION D consists of 2 case-based questions carrying 4 marks each.
6. SECTION E consists of 3 long answer questions carrying 5 marks each.
7. All questions are compulsory.
8. The use of log tables and calculators is not allowed
Section A
a) 237.6°F b) -317.6°F
c) 317.6 °F d) -187.6°F
1. -122°C in Fahrenheit scale is [1]
a) 3p b) 3d
c) 3s d) 3f
2. The orbital with n = 3 and l = 2 is [1]
a) is never negative. b) may be positive or negative.
c) is always negative. d) is always positive.
3. The enthalpies of elements in their standard states are taken as zero. The enthalpy of formation of a compound
is:
[1]
a) 14 b) 32
c) 16 d) 12
4. Maximum number of electrons in a subshell with l = 3 and n = 4 is _____. [1]
a) 30.0 kJ b) 42.0 kJ
c) 34.0 kJ d) 23.0 kJ
5. To vaporize 100.0 g carbon tetrachloride at its normal boiling point, 349.9 K, and P =1 atm, 19.5 kJ of heat is
required. Calculate  for CCl
4
?
[1]
? H v a p 6. The energy associated with the first orbit in the hydrogen atom is -2.18 10
-18
 J/atom. Calculate the radius of
[1]
× Page 1 of 12
a) 1.3225 nm b) 13.2250 nm
c) 2.3225 nm d) 0.13225 nm
Bohr’s fifth orbit for hydrogen atom.
a) reduction process b) All of these
c) addition process d) oxidation process
7. In the given reaction, 
CH
2
 = CH
2
(g) + H
2
(g)  CH
3
 - CH
3
(g) 
ethene undergoes 
[1]
? a) Chromatography b) Spectroscopy
c) Differential Extraction d) Distillation under reduced pressure
8. To which the terms stationary phase and mobile phase are associated? [1]
a) Ethyne b) Methane
c) Ethene d) Ethane
9. What product is obtained by heating ethylidene chloride with alcoholic KOH? [1]
a) 1.36, 1.71, 1.40 b) 1.36, 1.40, 1.71
c) 1.71, 1.40, 1.36 d) 1.71, 1.36, 1.40
10. The ionic radii of N
3-
, O
2-
 and F
-
 are respectively given by:
[1]
a) The boundaries permit the flow of matter
into it but not vice versa.
b) The boundaries permit the flow of matter
into or out of it.
c) The boundaries prevent the flow of matter
into or out of it.
d) The boundaries prevent the flow of matter
out of it but not vice versa.
11. In a closed system, which of the following take place? [1]
a) infinite b) zero
c) one d) two
12. The number of possible conformational isomers of ethane is ________. [1]
a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the
correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
13. Assertion (A): The term tautomerism was introduced by Maxwell in order to explain the chemical reactivity of
a substance according to two possible structures. 
Reason (R): Metamers can also be chain isomers or position isomers.
[1]
a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the
correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
14. Assertion (A): C
6
H
5
F gives large amount of nitration products than all the other halides. 
Reason (R): F is most electronegative.
[1]
Page 2 of 12
Section B
Section C
a) If both Assertion & Reason are true and the
reason is the correct explanation of the
assertion.
b) If both Assertion & Reason are true but the
reason is not the correct explanation of the
assertion.
c) If Assertion is true statement but Reason is
false.
d) If both Assertion and Reason are false
statements.
15. Assertion: A spectral line will be seen for a  transition. 
Reason: Energy is released in the form of waves of light when the electron drops from 2p
v
 to 2p orbital.
[1] 2 ? 2 p x p y a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the
correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
16. Assertion (A): Both 32 g of SO
2
 and 8 g of CH
4
 contain the same number of molecules. 
Reason (R): Equal moles of two compounds contain the same number of molecules.
[1]
17. Calculate the solubility of A
2
X
3
 in pure water, assuming that neither kind of ion reacts with water. The solubility
product of A
2
X
3
, K
sp
 = 1.1  10
–23
.
[2]
× 18. The electron gain enthalpy of bromine is 3.36 eV. How much energy in kcal is released when 8 g of bromine is
completely converted to Br
- 
ions in the gaseous state?  
(1 eV = 23.06 kcal mol
-1
).
[2]
19. The element H and O combine separately with the third element S to form H
2
S and SO
2
 respectively, then show
that they combine directly with each other to from H
2
O. 
[2]
20. Write the structure and IUPAC names of different structural isomers of alkenes corresponding to C
5
H
10
. [2]
OR
Write hydrocarbon radicals that can be formed as intermediates during monochlorination of 2-methylpropane. Which
of them is more stable? Give reasons.
21. Prove that the density of the nucleus is constant. [2]
22. Write Lewis symbols for the following atoms and ions: 
S and S
2–
; Al and Al
3+
; H and H
–
[3]
23. Answer: [3]
Consider the same expansion, but this time against a constant external pressure of 1 atm. [1] (a)
What do you mean by entropy? [1] (b)
Air contains about 99% of N
2
 and O
2
 gases. Why they do not combine to form NO under the standard
conditions? Standard Gibbs energy of formation of NO(g) is 86.7 kJ mol
-1
.
[1] (c)
24. Assuming the water vapor to be a perfect gas, calculate the internal energy change when 1 mol of water at 100°C [3]
Page 3 of 12
Page 4


Time Allowed: 3 hours Maximum Marks: 70 
General Instructions:
1. There are 33 questions in this question paper with internal choice.
2. SECTION A consists of 16 multiple-choice questions carrying 1 mark each.
3. SECTION B consists of 5 very short answer questions carrying 2 marks each.
4. SECTION C consists of 7 short answer questions carrying 3 marks each.
5. SECTION D consists of 2 case-based questions carrying 4 marks each.
6. SECTION E consists of 3 long answer questions carrying 5 marks each.
7. All questions are compulsory.
8. The use of log tables and calculators is not allowed
Section A
a) 237.6°F b) -317.6°F
c) 317.6 °F d) -187.6°F
1. -122°C in Fahrenheit scale is [1]
a) 3p b) 3d
c) 3s d) 3f
2. The orbital with n = 3 and l = 2 is [1]
a) is never negative. b) may be positive or negative.
c) is always negative. d) is always positive.
3. The enthalpies of elements in their standard states are taken as zero. The enthalpy of formation of a compound
is:
[1]
a) 14 b) 32
c) 16 d) 12
4. Maximum number of electrons in a subshell with l = 3 and n = 4 is _____. [1]
a) 30.0 kJ b) 42.0 kJ
c) 34.0 kJ d) 23.0 kJ
5. To vaporize 100.0 g carbon tetrachloride at its normal boiling point, 349.9 K, and P =1 atm, 19.5 kJ of heat is
required. Calculate  for CCl
4
?
[1]
? H v a p 6. The energy associated with the first orbit in the hydrogen atom is -2.18 10
-18
 J/atom. Calculate the radius of
[1]
× Page 1 of 12
a) 1.3225 nm b) 13.2250 nm
c) 2.3225 nm d) 0.13225 nm
Bohr’s fifth orbit for hydrogen atom.
a) reduction process b) All of these
c) addition process d) oxidation process
7. In the given reaction, 
CH
2
 = CH
2
(g) + H
2
(g)  CH
3
 - CH
3
(g) 
ethene undergoes 
[1]
? a) Chromatography b) Spectroscopy
c) Differential Extraction d) Distillation under reduced pressure
8. To which the terms stationary phase and mobile phase are associated? [1]
a) Ethyne b) Methane
c) Ethene d) Ethane
9. What product is obtained by heating ethylidene chloride with alcoholic KOH? [1]
a) 1.36, 1.71, 1.40 b) 1.36, 1.40, 1.71
c) 1.71, 1.40, 1.36 d) 1.71, 1.36, 1.40
10. The ionic radii of N
3-
, O
2-
 and F
-
 are respectively given by:
[1]
a) The boundaries permit the flow of matter
into it but not vice versa.
b) The boundaries permit the flow of matter
into or out of it.
c) The boundaries prevent the flow of matter
into or out of it.
d) The boundaries prevent the flow of matter
out of it but not vice versa.
11. In a closed system, which of the following take place? [1]
a) infinite b) zero
c) one d) two
12. The number of possible conformational isomers of ethane is ________. [1]
a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the
correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
13. Assertion (A): The term tautomerism was introduced by Maxwell in order to explain the chemical reactivity of
a substance according to two possible structures. 
Reason (R): Metamers can also be chain isomers or position isomers.
[1]
a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the
correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
14. Assertion (A): C
6
H
5
F gives large amount of nitration products than all the other halides. 
Reason (R): F is most electronegative.
[1]
Page 2 of 12
Section B
Section C
a) If both Assertion & Reason are true and the
reason is the correct explanation of the
assertion.
b) If both Assertion & Reason are true but the
reason is not the correct explanation of the
assertion.
c) If Assertion is true statement but Reason is
false.
d) If both Assertion and Reason are false
statements.
15. Assertion: A spectral line will be seen for a  transition. 
Reason: Energy is released in the form of waves of light when the electron drops from 2p
v
 to 2p orbital.
[1] 2 ? 2 p x p y a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the
correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
16. Assertion (A): Both 32 g of SO
2
 and 8 g of CH
4
 contain the same number of molecules. 
Reason (R): Equal moles of two compounds contain the same number of molecules.
[1]
17. Calculate the solubility of A
2
X
3
 in pure water, assuming that neither kind of ion reacts with water. The solubility
product of A
2
X
3
, K
sp
 = 1.1  10
–23
.
[2]
× 18. The electron gain enthalpy of bromine is 3.36 eV. How much energy in kcal is released when 8 g of bromine is
completely converted to Br
- 
ions in the gaseous state?  
(1 eV = 23.06 kcal mol
-1
).
[2]
19. The element H and O combine separately with the third element S to form H
2
S and SO
2
 respectively, then show
that they combine directly with each other to from H
2
O. 
[2]
20. Write the structure and IUPAC names of different structural isomers of alkenes corresponding to C
5
H
10
. [2]
OR
Write hydrocarbon radicals that can be formed as intermediates during monochlorination of 2-methylpropane. Which
of them is more stable? Give reasons.
21. Prove that the density of the nucleus is constant. [2]
22. Write Lewis symbols for the following atoms and ions: 
S and S
2–
; Al and Al
3+
; H and H
–
[3]
23. Answer: [3]
Consider the same expansion, but this time against a constant external pressure of 1 atm. [1] (a)
What do you mean by entropy? [1] (b)
Air contains about 99% of N
2
 and O
2
 gases. Why they do not combine to form NO under the standard
conditions? Standard Gibbs energy of formation of NO(g) is 86.7 kJ mol
-1
.
[1] (c)
24. Assuming the water vapor to be a perfect gas, calculate the internal energy change when 1 mol of water at 100°C [3]
Page 3 of 12
Section D
and 1 bar pressure is converted to the ice at 0°C. Given the enthalpy of fusion of ice is 6.00 kJ mol1 heat
capacity of water is 4.2 J/g°C.
25. PbO and PbO
2
 react with HCl according to the following chemical equations: 
2PbO + 4HCl  2PbCl
2 
+ 2H
2
O 
PbO
2 
+ 4HCl  PbCl
2
 + Cl
2 
+ 2H
2
O 
Why do these compounds differ in their reactivity?
[3]
? ? 26. Similar to electron diffraction, neutron diffraction microscope is also used for the determination of the structure
of molecules. If the wavelength used here is 800 pm. Calculate the characteristic velocity associated with the
neutron.
[3]
27. How do atomic radius vary in a period and in a group? How do you explain the variation? [3]
28. A sugar syrup of weight 214.2 g contains 34.2 g of sugar (C
12
H
22
O
11
). Calculate
i. molal concentration, and
ii. mole fraction of sugar in the syrup
[3]
29. Read the following text carefully and answer the questions that follow: 
Chromatography is an important technique extensively used to separate mixtures into their components, purify
compounds and also test the purity of compounds. Based on the principle involved, chromatography is classified
into different categories. Two of these are Adsorption chromatography and Partition chromatography. Two main
types of chromatographic techniques are based on the principle of differential adsorption column
chromatography, and thin-layer chromatography. Adsorption chromatography is based on the fact that different
compounds are adsorbed on an adsorbent to different degrees. Column chromatography involves the separation
of a mixture over a column of adsorbent (stationary phase) packed in a glass tube. Thin-layer chromatography
(TLC) is another type of adsorption chromatography, which involves the separation of substances of a mixture
over a thin layer of an adsorbent coated on a glass plate. Partition chromatography is based on the continuous
differential partitioning of components of a mixture between stationary and mobile phases.
i. Which adsorbent is used in adsorption chromatography?
ii. How do you visualize colourless compounds after separation in Paper Chromatography?
iii. Why paper chromatography is a type of partition chromatography? 
OR
Which chromatography is shown in following image? 
[4]
30. Read the following text carefully and answer the questions that follow: 
In order to explain the characteristic geometrical shapes of polyatomic molecules, Pauling introduced the
concept of hybridisation. The orbitals undergoing hybridisation should have nearly the same energy. There are
various type of hybridisations involving s, p and d-type of orbitals. The type of hybridisation gives the
characteristic shape of the molecule or ion.
[4]
Page 4 of 12
Page 5


Time Allowed: 3 hours Maximum Marks: 70 
General Instructions:
1. There are 33 questions in this question paper with internal choice.
2. SECTION A consists of 16 multiple-choice questions carrying 1 mark each.
3. SECTION B consists of 5 very short answer questions carrying 2 marks each.
4. SECTION C consists of 7 short answer questions carrying 3 marks each.
5. SECTION D consists of 2 case-based questions carrying 4 marks each.
6. SECTION E consists of 3 long answer questions carrying 5 marks each.
7. All questions are compulsory.
8. The use of log tables and calculators is not allowed
Section A
a) 237.6°F b) -317.6°F
c) 317.6 °F d) -187.6°F
1. -122°C in Fahrenheit scale is [1]
a) 3p b) 3d
c) 3s d) 3f
2. The orbital with n = 3 and l = 2 is [1]
a) is never negative. b) may be positive or negative.
c) is always negative. d) is always positive.
3. The enthalpies of elements in their standard states are taken as zero. The enthalpy of formation of a compound
is:
[1]
a) 14 b) 32
c) 16 d) 12
4. Maximum number of electrons in a subshell with l = 3 and n = 4 is _____. [1]
a) 30.0 kJ b) 42.0 kJ
c) 34.0 kJ d) 23.0 kJ
5. To vaporize 100.0 g carbon tetrachloride at its normal boiling point, 349.9 K, and P =1 atm, 19.5 kJ of heat is
required. Calculate  for CCl
4
?
[1]
? H v a p 6. The energy associated with the first orbit in the hydrogen atom is -2.18 10
-18
 J/atom. Calculate the radius of
[1]
× Page 1 of 12
a) 1.3225 nm b) 13.2250 nm
c) 2.3225 nm d) 0.13225 nm
Bohr’s fifth orbit for hydrogen atom.
a) reduction process b) All of these
c) addition process d) oxidation process
7. In the given reaction, 
CH
2
 = CH
2
(g) + H
2
(g)  CH
3
 - CH
3
(g) 
ethene undergoes 
[1]
? a) Chromatography b) Spectroscopy
c) Differential Extraction d) Distillation under reduced pressure
8. To which the terms stationary phase and mobile phase are associated? [1]
a) Ethyne b) Methane
c) Ethene d) Ethane
9. What product is obtained by heating ethylidene chloride with alcoholic KOH? [1]
a) 1.36, 1.71, 1.40 b) 1.36, 1.40, 1.71
c) 1.71, 1.40, 1.36 d) 1.71, 1.36, 1.40
10. The ionic radii of N
3-
, O
2-
 and F
-
 are respectively given by:
[1]
a) The boundaries permit the flow of matter
into it but not vice versa.
b) The boundaries permit the flow of matter
into or out of it.
c) The boundaries prevent the flow of matter
into or out of it.
d) The boundaries prevent the flow of matter
out of it but not vice versa.
11. In a closed system, which of the following take place? [1]
a) infinite b) zero
c) one d) two
12. The number of possible conformational isomers of ethane is ________. [1]
a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the
correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
13. Assertion (A): The term tautomerism was introduced by Maxwell in order to explain the chemical reactivity of
a substance according to two possible structures. 
Reason (R): Metamers can also be chain isomers or position isomers.
[1]
a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the
correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
14. Assertion (A): C
6
H
5
F gives large amount of nitration products than all the other halides. 
Reason (R): F is most electronegative.
[1]
Page 2 of 12
Section B
Section C
a) If both Assertion & Reason are true and the
reason is the correct explanation of the
assertion.
b) If both Assertion & Reason are true but the
reason is not the correct explanation of the
assertion.
c) If Assertion is true statement but Reason is
false.
d) If both Assertion and Reason are false
statements.
15. Assertion: A spectral line will be seen for a  transition. 
Reason: Energy is released in the form of waves of light when the electron drops from 2p
v
 to 2p orbital.
[1] 2 ? 2 p x p y a) Both A and R are true and R is the correct
explanation of A.
b) Both A and R are true but R is not the
correct explanation of A.
c) A is true but R is false. d) A is false but R is true.
16. Assertion (A): Both 32 g of SO
2
 and 8 g of CH
4
 contain the same number of molecules. 
Reason (R): Equal moles of two compounds contain the same number of molecules.
[1]
17. Calculate the solubility of A
2
X
3
 in pure water, assuming that neither kind of ion reacts with water. The solubility
product of A
2
X
3
, K
sp
 = 1.1  10
–23
.
[2]
× 18. The electron gain enthalpy of bromine is 3.36 eV. How much energy in kcal is released when 8 g of bromine is
completely converted to Br
- 
ions in the gaseous state?  
(1 eV = 23.06 kcal mol
-1
).
[2]
19. The element H and O combine separately with the third element S to form H
2
S and SO
2
 respectively, then show
that they combine directly with each other to from H
2
O. 
[2]
20. Write the structure and IUPAC names of different structural isomers of alkenes corresponding to C
5
H
10
. [2]
OR
Write hydrocarbon radicals that can be formed as intermediates during monochlorination of 2-methylpropane. Which
of them is more stable? Give reasons.
21. Prove that the density of the nucleus is constant. [2]
22. Write Lewis symbols for the following atoms and ions: 
S and S
2–
; Al and Al
3+
; H and H
–
[3]
23. Answer: [3]
Consider the same expansion, but this time against a constant external pressure of 1 atm. [1] (a)
What do you mean by entropy? [1] (b)
Air contains about 99% of N
2
 and O
2
 gases. Why they do not combine to form NO under the standard
conditions? Standard Gibbs energy of formation of NO(g) is 86.7 kJ mol
-1
.
[1] (c)
24. Assuming the water vapor to be a perfect gas, calculate the internal energy change when 1 mol of water at 100°C [3]
Page 3 of 12
Section D
and 1 bar pressure is converted to the ice at 0°C. Given the enthalpy of fusion of ice is 6.00 kJ mol1 heat
capacity of water is 4.2 J/g°C.
25. PbO and PbO
2
 react with HCl according to the following chemical equations: 
2PbO + 4HCl  2PbCl
2 
+ 2H
2
O 
PbO
2 
+ 4HCl  PbCl
2
 + Cl
2 
+ 2H
2
O 
Why do these compounds differ in their reactivity?
[3]
? ? 26. Similar to electron diffraction, neutron diffraction microscope is also used for the determination of the structure
of molecules. If the wavelength used here is 800 pm. Calculate the characteristic velocity associated with the
neutron.
[3]
27. How do atomic radius vary in a period and in a group? How do you explain the variation? [3]
28. A sugar syrup of weight 214.2 g contains 34.2 g of sugar (C
12
H
22
O
11
). Calculate
i. molal concentration, and
ii. mole fraction of sugar in the syrup
[3]
29. Read the following text carefully and answer the questions that follow: 
Chromatography is an important technique extensively used to separate mixtures into their components, purify
compounds and also test the purity of compounds. Based on the principle involved, chromatography is classified
into different categories. Two of these are Adsorption chromatography and Partition chromatography. Two main
types of chromatographic techniques are based on the principle of differential adsorption column
chromatography, and thin-layer chromatography. Adsorption chromatography is based on the fact that different
compounds are adsorbed on an adsorbent to different degrees. Column chromatography involves the separation
of a mixture over a column of adsorbent (stationary phase) packed in a glass tube. Thin-layer chromatography
(TLC) is another type of adsorption chromatography, which involves the separation of substances of a mixture
over a thin layer of an adsorbent coated on a glass plate. Partition chromatography is based on the continuous
differential partitioning of components of a mixture between stationary and mobile phases.
i. Which adsorbent is used in adsorption chromatography?
ii. How do you visualize colourless compounds after separation in Paper Chromatography?
iii. Why paper chromatography is a type of partition chromatography? 
OR
Which chromatography is shown in following image? 
[4]
30. Read the following text carefully and answer the questions that follow: 
In order to explain the characteristic geometrical shapes of polyatomic molecules, Pauling introduced the
concept of hybridisation. The orbitals undergoing hybridisation should have nearly the same energy. There are
various type of hybridisations involving s, p and d-type of orbitals. The type of hybridisation gives the
characteristic shape of the molecule or ion.
[4]
Page 4 of 12
Section E
i. Why all the orbitals in a set of hybridised orbitals have the same shape and energy?
ii. Out of XeF
2
 and SF
2
 which molecule has the same shape as  ion?
iii. Out of XeF
4
 and XeF
2
 which molecule doesn't have the same type of hybridisation as P(Phosphorus) has in
PF
5
? 
OR
Unsaturated compounds undergo additional reactions. Why?
N O + 2 31. Attempt any five of the following: [5]
Convert methane into ethane. [1] (a)
Write IUPAC name of the following: CH
3
 (CH
2
)
4
 CH (CH
2
)
3
 CH
3
CH
2
 – CH (CH
3
)
2
[1] (b)
To which category of compounds does cyclohexane belong? [1] (c)
Name the type of hybridization in C (2) and C (3) in the following molecule [1] (d)
What are Arenes? [1] (e)
n-propylmagnesium bromide on hydrolysis gives propane. Is there any other Grignard reagent which
also gives propane? If so, give its name, structure and equation for the reaction.
[1] (f)
How will you distinguish between acetylene and ethylene? [1] (g)
32. The pH of milk, black coffee, tomato juice, lemon juice, and egg white are 6.8, 5.0, 4.2, 2.2 and 7.8 respectively.
Calculate corresponding hydrogen ion concentration in each.
[5]
OR
A sample of pure PCl
5
 was introduced into an evacuated vessel at 473 K. After equilibrium was attained,
concentration of PCl
5
 was found to be 0.5  10
-1
 mol L
-1
. If value of K
c
 is 8.3  10
-3
, what are the concentrations
of PCl
3
 and Cl
2
 at equilibrium? 
PCl
5
 (g)  PCl
3
 (g) + Cl
2
(g)
× × ? 33. Answer: [5]
i. What is the general molecular formula of saturated monohydric alcohols? [2.5]
ii. Write structural formulae for compounds named as-
a. 1-Bromoheptane
b. 5-Bromoheptanoic acid
[2.5]
(a)
OR
i. Explain hyperconjugation effect. How does hyperconjugation effect explain the stability of
alkenes?
[2.5]
ii. Draw the resonance structures of the following compounds:
i. 
ii. CH
2
 = CH — CH = CH
2
iii. 
[2.5]
C = C H - = O H 2 C | H Page 5 of 12