ICSE Chemistry Sample Paper - 2024 | ICSE Class 12 Science Sample Papers PDF Download

 Page 1


------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
1 
CHEMISTRY PAPER  1 
(THEORY) 
------------------------------------------------------------------------------------------------ 
Maximum Marks: 70 
Time Allowed: Three Hours 
(Candidates are allowed additional 15 minutes for only reading the paper. 
They must NOT start writing during this time.) 
---------------------------------------------------------------------------------------------------------------- 
This paper is divided into four sections – A, B, C and D. 
Answer all questions. 
Section – A consists of one question having sub-parts of one mark each. 
Section – B consists of ten questions of two marks each. 
Section – C consists of seven questions of three marks each, and 
Section – D consists of three questions of five marks each. 
Internal choices have been provided in one question each in Section B, 
Section C and Section D. 
All working, including rough work, should be done on the same sheet as, and adjacent to the 
rest of the answer. 
The intended marks for questions or parts of questions are given in brackets [ ]. 
Balanced equations must be given wherever possible and diagrams where they are helpful. 
When solving numerical problems, all essential working must be shown. 
In working out problems, use the following data: 
Gas constant R = 1 ?987 cal deg
-1
 mol
-1
 = 8 ?314 JK
-1
 mol
-1
 = 0 ?0821 dm
3
 atm K
-1
mol
-1
 
1 l  atm = 1 dm
3
 atm  = 101 ?3 J.  1 Faraday = 96500 coulombs.   
Avogadro’s number = 6 ?023 ?10
23
. 
---------------------------------------------------------------------------------------------------------------- 
SECTION A – 14 MARKS 
 
Question 1  
(A) Fill in the blanks by choosing the appropriate word(s) from those given in the 
brackets: 
[ decreases, CN
-
 ion, activation energy, catalyst, two, Fe
2+ 
ion, carbon, lattice 
energy, enzyme, five, double, halogen, triple, increases] 
[4×1] 
 (i) In the Haber process, iron changes the _______ of reaction while 
molybdenum increases the efficiency of the _________. 
 
 (ii) The number of ions that will be produced when potassium ferrocyanide, 
K4[Fe(CN)6], dissolves in water is _________. This shows that 
__________ is the ligand in the coordination compound. 
 
Page 2


------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
1 
CHEMISTRY PAPER  1 
(THEORY) 
------------------------------------------------------------------------------------------------ 
Maximum Marks: 70 
Time Allowed: Three Hours 
(Candidates are allowed additional 15 minutes for only reading the paper. 
They must NOT start writing during this time.) 
---------------------------------------------------------------------------------------------------------------- 
This paper is divided into four sections – A, B, C and D. 
Answer all questions. 
Section – A consists of one question having sub-parts of one mark each. 
Section – B consists of ten questions of two marks each. 
Section – C consists of seven questions of three marks each, and 
Section – D consists of three questions of five marks each. 
Internal choices have been provided in one question each in Section B, 
Section C and Section D. 
All working, including rough work, should be done on the same sheet as, and adjacent to the 
rest of the answer. 
The intended marks for questions or parts of questions are given in brackets [ ]. 
Balanced equations must be given wherever possible and diagrams where they are helpful. 
When solving numerical problems, all essential working must be shown. 
In working out problems, use the following data: 
Gas constant R = 1 ?987 cal deg
-1
 mol
-1
 = 8 ?314 JK
-1
 mol
-1
 = 0 ?0821 dm
3
 atm K
-1
mol
-1
 
1 l  atm = 1 dm
3
 atm  = 101 ?3 J.  1 Faraday = 96500 coulombs.   
Avogadro’s number = 6 ?023 ?10
23
. 
---------------------------------------------------------------------------------------------------------------- 
SECTION A – 14 MARKS 
 
Question 1  
(A) Fill in the blanks by choosing the appropriate word(s) from those given in the 
brackets: 
[ decreases, CN
-
 ion, activation energy, catalyst, two, Fe
2+ 
ion, carbon, lattice 
energy, enzyme, five, double, halogen, triple, increases] 
[4×1] 
 (i) In the Haber process, iron changes the _______ of reaction while 
molybdenum increases the efficiency of the _________. 
 
 (ii) The number of ions that will be produced when potassium ferrocyanide, 
K4[Fe(CN)6], dissolves in water is _________. This shows that 
__________ is the ligand in the coordination compound. 
 
------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
2 
 (iii) Haloalkenes undergo both nucleophilic and electrophilic reactions due to 
the presence of __________bond and the __________ atom. 
 
 (iv) In case of alcohols, as the carbon chain length increases, the boiling 
point ____________ and the solubility in water____________. 
 
(B) Select and write the correct alternative from the choices given below: [7×1] 
 (i) A potassium iodide (KI) solution containing starch turns blue on the 
addition of chlorine. Which one of the following statements explain this? 
(P) The reduction potential of Cl2 is more than that of I2. 
(Q) The oxidation potential of Cl2 is more than that of I2. 
(R) The product formed when Cl2 combines with starch is blue. 
(S) The product formed when I2 combines with starch is blue. 
 
  (a) Only P and R  
  (b) Only Q and R   
  (c) Only Q and S   
  (d) Only P and S   
 (ii) Crystal field splitting energy (CFSE) for high spin d
4
 octahedral complex 
is: 
 
  (a) -1·6 ?o  
  (b) -1·2 ?o  
  (c) -0·8 ?o  
  (d) -0·6 ?o  
 (iii) Acidified K2Cr2O7 solution turns green when Na2SO3 is added to it. This 
is due to formation of: 
 
  (a) CrO4
2-
  
  (b) Cr2(SO3)3  
  (c) Cr2O3  
  (d) Cr2(SO4)3  
 (iv) Which of the following product is formed when benzene diazonium 
chloride is reduced by hypophosphorous acid (H3PO2) in the presence of 
cuprous ion as catalyst? 
 
  (a) Phenol  
Page 3


------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
1 
CHEMISTRY PAPER  1 
(THEORY) 
------------------------------------------------------------------------------------------------ 
Maximum Marks: 70 
Time Allowed: Three Hours 
(Candidates are allowed additional 15 minutes for only reading the paper. 
They must NOT start writing during this time.) 
---------------------------------------------------------------------------------------------------------------- 
This paper is divided into four sections – A, B, C and D. 
Answer all questions. 
Section – A consists of one question having sub-parts of one mark each. 
Section – B consists of ten questions of two marks each. 
Section – C consists of seven questions of three marks each, and 
Section – D consists of three questions of five marks each. 
Internal choices have been provided in one question each in Section B, 
Section C and Section D. 
All working, including rough work, should be done on the same sheet as, and adjacent to the 
rest of the answer. 
The intended marks for questions or parts of questions are given in brackets [ ]. 
Balanced equations must be given wherever possible and diagrams where they are helpful. 
When solving numerical problems, all essential working must be shown. 
In working out problems, use the following data: 
Gas constant R = 1 ?987 cal deg
-1
 mol
-1
 = 8 ?314 JK
-1
 mol
-1
 = 0 ?0821 dm
3
 atm K
-1
mol
-1
 
1 l  atm = 1 dm
3
 atm  = 101 ?3 J.  1 Faraday = 96500 coulombs.   
Avogadro’s number = 6 ?023 ?10
23
. 
---------------------------------------------------------------------------------------------------------------- 
SECTION A – 14 MARKS 
 
Question 1  
(A) Fill in the blanks by choosing the appropriate word(s) from those given in the 
brackets: 
[ decreases, CN
-
 ion, activation energy, catalyst, two, Fe
2+ 
ion, carbon, lattice 
energy, enzyme, five, double, halogen, triple, increases] 
[4×1] 
 (i) In the Haber process, iron changes the _______ of reaction while 
molybdenum increases the efficiency of the _________. 
 
 (ii) The number of ions that will be produced when potassium ferrocyanide, 
K4[Fe(CN)6], dissolves in water is _________. This shows that 
__________ is the ligand in the coordination compound. 
 
------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
2 
 (iii) Haloalkenes undergo both nucleophilic and electrophilic reactions due to 
the presence of __________bond and the __________ atom. 
 
 (iv) In case of alcohols, as the carbon chain length increases, the boiling 
point ____________ and the solubility in water____________. 
 
(B) Select and write the correct alternative from the choices given below: [7×1] 
 (i) A potassium iodide (KI) solution containing starch turns blue on the 
addition of chlorine. Which one of the following statements explain this? 
(P) The reduction potential of Cl2 is more than that of I2. 
(Q) The oxidation potential of Cl2 is more than that of I2. 
(R) The product formed when Cl2 combines with starch is blue. 
(S) The product formed when I2 combines with starch is blue. 
 
  (a) Only P and R  
  (b) Only Q and R   
  (c) Only Q and S   
  (d) Only P and S   
 (ii) Crystal field splitting energy (CFSE) for high spin d
4
 octahedral complex 
is: 
 
  (a) -1·6 ?o  
  (b) -1·2 ?o  
  (c) -0·8 ?o  
  (d) -0·6 ?o  
 (iii) Acidified K2Cr2O7 solution turns green when Na2SO3 is added to it. This 
is due to formation of: 
 
  (a) CrO4
2-
  
  (b) Cr2(SO3)3  
  (c) Cr2O3  
  (d) Cr2(SO4)3  
 (iv) Which of the following product is formed when benzene diazonium 
chloride is reduced by hypophosphorous acid (H3PO2) in the presence of 
cuprous ion as catalyst? 
 
  (a) Phenol  
 
------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
3 
  (b) Aniline  
  (c) Benzene  
  (d) Benzene cyanide  
 (v) Which of the following aqueous solution has lowest vapour pressure?  
  (a) 1M NaCl  
  (b) 1M K2SO4  
  (c) 1M Glucose  
  (d) 1M Sucrose  
 (vi) Assertion: Adding water to two beakers ‘A’ and ‘B’ containing NaOH 
and CH3COOH solutions respectively will increase the molar 
conductance ( ?m) of the solutions sharply in beaker ‘A’ and 
slowly in beaker ‘B’. 
Reason: Molar conductance ( ?m) increases with a decrease in  
concentration or upon dilution. 
 
  (a) Both Assertion and Reason are true and Reason is the correct 
explanation of Assertion. 
 
  (b) Both Assertion and Reason are true but Reason is not the correct 
explanation for Assertion. 
 
  (c) Assertion is true but Reason is false.  
  (d) Assertion is false but Reason is true.  
 (vii) Assertion: Aniline is soluble in HCl while it is only slightly soluble in 
water. 
Reason: Aniline cannot make hydrogen bonds with water but gets 
protonated easily by acids. 
 
  (a) Both Assertion and Reason are true and Reason is the correct 
explanation of Assertion. 
 
  (b) Both Assertion and Reason are true but Reason is not the correct 
explanation for Assertion. 
 
  (c) Assertion is true but Reason is false.  
  (d) Assertion is false but Reason is true. 
 
 
Page 4


------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
1 
CHEMISTRY PAPER  1 
(THEORY) 
------------------------------------------------------------------------------------------------ 
Maximum Marks: 70 
Time Allowed: Three Hours 
(Candidates are allowed additional 15 minutes for only reading the paper. 
They must NOT start writing during this time.) 
---------------------------------------------------------------------------------------------------------------- 
This paper is divided into four sections – A, B, C and D. 
Answer all questions. 
Section – A consists of one question having sub-parts of one mark each. 
Section – B consists of ten questions of two marks each. 
Section – C consists of seven questions of three marks each, and 
Section – D consists of three questions of five marks each. 
Internal choices have been provided in one question each in Section B, 
Section C and Section D. 
All working, including rough work, should be done on the same sheet as, and adjacent to the 
rest of the answer. 
The intended marks for questions or parts of questions are given in brackets [ ]. 
Balanced equations must be given wherever possible and diagrams where they are helpful. 
When solving numerical problems, all essential working must be shown. 
In working out problems, use the following data: 
Gas constant R = 1 ?987 cal deg
-1
 mol
-1
 = 8 ?314 JK
-1
 mol
-1
 = 0 ?0821 dm
3
 atm K
-1
mol
-1
 
1 l  atm = 1 dm
3
 atm  = 101 ?3 J.  1 Faraday = 96500 coulombs.   
Avogadro’s number = 6 ?023 ?10
23
. 
---------------------------------------------------------------------------------------------------------------- 
SECTION A – 14 MARKS 
 
Question 1  
(A) Fill in the blanks by choosing the appropriate word(s) from those given in the 
brackets: 
[ decreases, CN
-
 ion, activation energy, catalyst, two, Fe
2+ 
ion, carbon, lattice 
energy, enzyme, five, double, halogen, triple, increases] 
[4×1] 
 (i) In the Haber process, iron changes the _______ of reaction while 
molybdenum increases the efficiency of the _________. 
 
 (ii) The number of ions that will be produced when potassium ferrocyanide, 
K4[Fe(CN)6], dissolves in water is _________. This shows that 
__________ is the ligand in the coordination compound. 
 
------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
2 
 (iii) Haloalkenes undergo both nucleophilic and electrophilic reactions due to 
the presence of __________bond and the __________ atom. 
 
 (iv) In case of alcohols, as the carbon chain length increases, the boiling 
point ____________ and the solubility in water____________. 
 
(B) Select and write the correct alternative from the choices given below: [7×1] 
 (i) A potassium iodide (KI) solution containing starch turns blue on the 
addition of chlorine. Which one of the following statements explain this? 
(P) The reduction potential of Cl2 is more than that of I2. 
(Q) The oxidation potential of Cl2 is more than that of I2. 
(R) The product formed when Cl2 combines with starch is blue. 
(S) The product formed when I2 combines with starch is blue. 
 
  (a) Only P and R  
  (b) Only Q and R   
  (c) Only Q and S   
  (d) Only P and S   
 (ii) Crystal field splitting energy (CFSE) for high spin d
4
 octahedral complex 
is: 
 
  (a) -1·6 ?o  
  (b) -1·2 ?o  
  (c) -0·8 ?o  
  (d) -0·6 ?o  
 (iii) Acidified K2Cr2O7 solution turns green when Na2SO3 is added to it. This 
is due to formation of: 
 
  (a) CrO4
2-
  
  (b) Cr2(SO3)3  
  (c) Cr2O3  
  (d) Cr2(SO4)3  
 (iv) Which of the following product is formed when benzene diazonium 
chloride is reduced by hypophosphorous acid (H3PO2) in the presence of 
cuprous ion as catalyst? 
 
  (a) Phenol  
 
------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
3 
  (b) Aniline  
  (c) Benzene  
  (d) Benzene cyanide  
 (v) Which of the following aqueous solution has lowest vapour pressure?  
  (a) 1M NaCl  
  (b) 1M K2SO4  
  (c) 1M Glucose  
  (d) 1M Sucrose  
 (vi) Assertion: Adding water to two beakers ‘A’ and ‘B’ containing NaOH 
and CH3COOH solutions respectively will increase the molar 
conductance ( ?m) of the solutions sharply in beaker ‘A’ and 
slowly in beaker ‘B’. 
Reason: Molar conductance ( ?m) increases with a decrease in  
concentration or upon dilution. 
 
  (a) Both Assertion and Reason are true and Reason is the correct 
explanation of Assertion. 
 
  (b) Both Assertion and Reason are true but Reason is not the correct 
explanation for Assertion. 
 
  (c) Assertion is true but Reason is false.  
  (d) Assertion is false but Reason is true.  
 (vii) Assertion: Aniline is soluble in HCl while it is only slightly soluble in 
water. 
Reason: Aniline cannot make hydrogen bonds with water but gets 
protonated easily by acids. 
 
  (a) Both Assertion and Reason are true and Reason is the correct 
explanation of Assertion. 
 
  (b) Both Assertion and Reason are true but Reason is not the correct 
explanation for Assertion. 
 
  (c) Assertion is true but Reason is false.  
  (d) Assertion is false but Reason is true. 
 
 
------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
4 
(C) Read the passage given below carefully and answer the questions that follow. [3×1] 
 During the winter season in a particular year, Kashmir experienced heavy 
snowfall. It was an unexpected snowfall. Thousands of visitors were stranded 
because it was dangerous to travel on snowy roads and vehicles could not move 
as water froze in the car radiators. In such conditions officials decided to sprinkle 
rock salt or CaCl2 on roads. 
 
 (i) Why was it decided to sprinkle rock salt or CaCl2 on the roads?  
 (ii) A mixture of ethylene glycol and water is used as coolant in car radiators. 
Why? 
 
 (iii) How many grams of ethylene glycol (mol. wt. = 62 g mol
-1
) should be 
added to 10 kg of water so that the solution freezes at -10
o
C?  
(Kf for water = 1?86 K kg mol
-1
) 
 
 
SECTION B – 20 MARKS 
 
Question 2 [2] 
(i) Arrange the following alcohols in order of decreasing activity towards Lucas’ 
reagent. 
2-butanol, 2-methyl-2-propanol and 1-butanol 
 
(ii) Ethanol has a higher boiling point than methoxymethane. Justify the statement.  
 
 
Question 3 [2] 
Give a reason for each of the following:  
(i) The size of the trivalent cations in Lanthanoid series decreases steadily as the 
atomic number increases. 
 
(ii) The third ionization energy of manganese (Z = 25) is unexpectedly high.  
 
 
Question 4 [2] 
Give balanced chemical equations to convert the following:  
(i) Benzene to biphenyl  
(ii) Propene to propane -1-ol  
 
 
 
Page 5


------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
1 
CHEMISTRY PAPER  1 
(THEORY) 
------------------------------------------------------------------------------------------------ 
Maximum Marks: 70 
Time Allowed: Three Hours 
(Candidates are allowed additional 15 minutes for only reading the paper. 
They must NOT start writing during this time.) 
---------------------------------------------------------------------------------------------------------------- 
This paper is divided into four sections – A, B, C and D. 
Answer all questions. 
Section – A consists of one question having sub-parts of one mark each. 
Section – B consists of ten questions of two marks each. 
Section – C consists of seven questions of three marks each, and 
Section – D consists of three questions of five marks each. 
Internal choices have been provided in one question each in Section B, 
Section C and Section D. 
All working, including rough work, should be done on the same sheet as, and adjacent to the 
rest of the answer. 
The intended marks for questions or parts of questions are given in brackets [ ]. 
Balanced equations must be given wherever possible and diagrams where they are helpful. 
When solving numerical problems, all essential working must be shown. 
In working out problems, use the following data: 
Gas constant R = 1 ?987 cal deg
-1
 mol
-1
 = 8 ?314 JK
-1
 mol
-1
 = 0 ?0821 dm
3
 atm K
-1
mol
-1
 
1 l  atm = 1 dm
3
 atm  = 101 ?3 J.  1 Faraday = 96500 coulombs.   
Avogadro’s number = 6 ?023 ?10
23
. 
---------------------------------------------------------------------------------------------------------------- 
SECTION A – 14 MARKS 
 
Question 1  
(A) Fill in the blanks by choosing the appropriate word(s) from those given in the 
brackets: 
[ decreases, CN
-
 ion, activation energy, catalyst, two, Fe
2+ 
ion, carbon, lattice 
energy, enzyme, five, double, halogen, triple, increases] 
[4×1] 
 (i) In the Haber process, iron changes the _______ of reaction while 
molybdenum increases the efficiency of the _________. 
 
 (ii) The number of ions that will be produced when potassium ferrocyanide, 
K4[Fe(CN)6], dissolves in water is _________. This shows that 
__________ is the ligand in the coordination compound. 
 
------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
2 
 (iii) Haloalkenes undergo both nucleophilic and electrophilic reactions due to 
the presence of __________bond and the __________ atom. 
 
 (iv) In case of alcohols, as the carbon chain length increases, the boiling 
point ____________ and the solubility in water____________. 
 
(B) Select and write the correct alternative from the choices given below: [7×1] 
 (i) A potassium iodide (KI) solution containing starch turns blue on the 
addition of chlorine. Which one of the following statements explain this? 
(P) The reduction potential of Cl2 is more than that of I2. 
(Q) The oxidation potential of Cl2 is more than that of I2. 
(R) The product formed when Cl2 combines with starch is blue. 
(S) The product formed when I2 combines with starch is blue. 
 
  (a) Only P and R  
  (b) Only Q and R   
  (c) Only Q and S   
  (d) Only P and S   
 (ii) Crystal field splitting energy (CFSE) for high spin d
4
 octahedral complex 
is: 
 
  (a) -1·6 ?o  
  (b) -1·2 ?o  
  (c) -0·8 ?o  
  (d) -0·6 ?o  
 (iii) Acidified K2Cr2O7 solution turns green when Na2SO3 is added to it. This 
is due to formation of: 
 
  (a) CrO4
2-
  
  (b) Cr2(SO3)3  
  (c) Cr2O3  
  (d) Cr2(SO4)3  
 (iv) Which of the following product is formed when benzene diazonium 
chloride is reduced by hypophosphorous acid (H3PO2) in the presence of 
cuprous ion as catalyst? 
 
  (a) Phenol  
 
------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
3 
  (b) Aniline  
  (c) Benzene  
  (d) Benzene cyanide  
 (v) Which of the following aqueous solution has lowest vapour pressure?  
  (a) 1M NaCl  
  (b) 1M K2SO4  
  (c) 1M Glucose  
  (d) 1M Sucrose  
 (vi) Assertion: Adding water to two beakers ‘A’ and ‘B’ containing NaOH 
and CH3COOH solutions respectively will increase the molar 
conductance ( ?m) of the solutions sharply in beaker ‘A’ and 
slowly in beaker ‘B’. 
Reason: Molar conductance ( ?m) increases with a decrease in  
concentration or upon dilution. 
 
  (a) Both Assertion and Reason are true and Reason is the correct 
explanation of Assertion. 
 
  (b) Both Assertion and Reason are true but Reason is not the correct 
explanation for Assertion. 
 
  (c) Assertion is true but Reason is false.  
  (d) Assertion is false but Reason is true.  
 (vii) Assertion: Aniline is soluble in HCl while it is only slightly soluble in 
water. 
Reason: Aniline cannot make hydrogen bonds with water but gets 
protonated easily by acids. 
 
  (a) Both Assertion and Reason are true and Reason is the correct 
explanation of Assertion. 
 
  (b) Both Assertion and Reason are true but Reason is not the correct 
explanation for Assertion. 
 
  (c) Assertion is true but Reason is false.  
  (d) Assertion is false but Reason is true. 
 
 
------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
4 
(C) Read the passage given below carefully and answer the questions that follow. [3×1] 
 During the winter season in a particular year, Kashmir experienced heavy 
snowfall. It was an unexpected snowfall. Thousands of visitors were stranded 
because it was dangerous to travel on snowy roads and vehicles could not move 
as water froze in the car radiators. In such conditions officials decided to sprinkle 
rock salt or CaCl2 on roads. 
 
 (i) Why was it decided to sprinkle rock salt or CaCl2 on the roads?  
 (ii) A mixture of ethylene glycol and water is used as coolant in car radiators. 
Why? 
 
 (iii) How many grams of ethylene glycol (mol. wt. = 62 g mol
-1
) should be 
added to 10 kg of water so that the solution freezes at -10
o
C?  
(Kf for water = 1?86 K kg mol
-1
) 
 
 
SECTION B – 20 MARKS 
 
Question 2 [2] 
(i) Arrange the following alcohols in order of decreasing activity towards Lucas’ 
reagent. 
2-butanol, 2-methyl-2-propanol and 1-butanol 
 
(ii) Ethanol has a higher boiling point than methoxymethane. Justify the statement.  
 
 
Question 3 [2] 
Give a reason for each of the following:  
(i) The size of the trivalent cations in Lanthanoid series decreases steadily as the 
atomic number increases. 
 
(ii) The third ionization energy of manganese (Z = 25) is unexpectedly high.  
 
 
Question 4 [2] 
Give balanced chemical equations to convert the following:  
(i) Benzene to biphenyl  
(ii) Propene to propane -1-ol  
 
 
 
 
------------------------------------------------------------------------------------------------------------------- 
ISC SPECIMEN QUESTION PAPER 2024 
5 
Question 5 [2] 
Account for the following: 
 
(i) Salts of cuprous (Cu
+
) ion are colourless whereas the salts of cupric (Cu
2+
) ion are 
coloured. 
 
(ii) Zinc is not regarded as a transition element. (at. no. of Zn = 30)  
 
 
 Question 6 [2] 
Two compounds, D-2-chlorobutane and L-2-chlorobutane, are enantiomers of each 
other. 
 
Name one physical property that is:  
(i) same for D-2-chlorobutane and L-2-chlorobutane.  
(ii) different for D-2-chlorobutane and L-2-chlorobutane.  
 
 
Question 7 [2] 
(i) A rusted piece of iron undergoes electrochemical reactions. Write the chemical 
reaction taking place at: 
 
 (a) the electrode that behaves as an anode.  
 (b) the electrode that behaves as a cathode.  
(ii) Given that the standard reduction potential for Al
3+
/Al = -1?66 V and                                      
½ I2/I
- 
= 0?54V, what will be the standard potential of the cell made by using Al
3+
 
and I
-
? 
 
 
 
Question 8 [2] 
(i) What happens when (write chemical reactions only)  
 (a) Diethyl ether is treated with phosphorous pentachloride.  
 (b) Ethyl alcohol is treated with methyl magnesium bromide.  
 OR  
(ii) An organic compound [A] having molecular formula C6H6O gives a 
characteristic colour with aqueous FeCl3 solution. [A] on treatment with CO2 and 
NaOH at 400K under pressure gives [B] which on acidification gives compound 
[C]. [C] reacts with acetyl chloride to give [D] which is a popular pain killer.