s-Block Elements: JEE Mains Previous Year Questions (2021-2024) | Chemistry for JEE Main & Advanced PDF Download

 Page 1


Physical World, Units and Measurements P-1
Numerical 
 
 
JEE Main 2023 (Online) 29th January Evening Shift 
 
 
 
JEE Main 2023 (Online) 11th April Evening Shift 
 
Q.2. The number of alkali metal(s), from Li,K,Cs, Rb having 
ionization enthalpy greater than  400 kJ mol
-1
 and forming stable 
super oxide is _________. 
 
Q.1.  Mg(NO3)2·XH2O and Ba(NO3)2·YH2O, represent formula of the 
crystalline forms of nitrate salts. Sum of X and Y is __________ 
JEE Main 2023 (Online) 31st January Evening Shift 
 
Q.3. On heating, LiNO3 gives how many compounds among the 
following __________ 
Page 2


Physical World, Units and Measurements P-1
Numerical 
 
 
JEE Main 2023 (Online) 29th January Evening Shift 
 
 
 
JEE Main 2023 (Online) 11th April Evening Shift 
 
Q.2. The number of alkali metal(s), from Li,K,Cs, Rb having 
ionization enthalpy greater than  400 kJ mol
-1
 and forming stable 
super oxide is _________. 
 
Q.1.  Mg(NO3)2·XH2O and Ba(NO3)2·YH2O, represent formula of the 
crystalline forms of nitrate salts. Sum of X and Y is __________ 
JEE Main 2023 (Online) 31st January Evening Shift 
 
Q.3. On heating, LiNO3 gives how many compounds among the 
following __________ 
Answer Key & Explanation 
 
1. Ans. Correct answer is 6 
Explanation 
Magnesium nitrate typically crystallizes as a hexahydrate, which 
means it has six water molecules in its crystal structure. So, X = 6. 
Therefore, the sum of X and Y would indeed be 6 + 0 = 6. 
2. Ans. Correct answer is 2 
Explanation 
 
3. Ans. Correct answer is 3 
Explanation 
 
 
Li does not form superoxide. 
 
K, Rb and Cs form stable super oxides but Cs has ionisation 
enthalpy less than 400 kJ. While K and Rb have ionisation 
enthalpy greater than 400 kJ mol
–1
. 
On the other hand, barium nitrate commonly crystallizes as an 
anhydrous salt, meaning it does not incorporate water molecules 
into its crystal structure. So, Y = 0. 
Page 3


Physical World, Units and Measurements P-1
Numerical 
 
 
JEE Main 2023 (Online) 29th January Evening Shift 
 
 
 
JEE Main 2023 (Online) 11th April Evening Shift 
 
Q.2. The number of alkali metal(s), from Li,K,Cs, Rb having 
ionization enthalpy greater than  400 kJ mol
-1
 and forming stable 
super oxide is _________. 
 
Q.1.  Mg(NO3)2·XH2O and Ba(NO3)2·YH2O, represent formula of the 
crystalline forms of nitrate salts. Sum of X and Y is __________ 
JEE Main 2023 (Online) 31st January Evening Shift 
 
Q.3. On heating, LiNO3 gives how many compounds among the 
following __________ 
Answer Key & Explanation 
 
1. Ans. Correct answer is 6 
Explanation 
Magnesium nitrate typically crystallizes as a hexahydrate, which 
means it has six water molecules in its crystal structure. So, X = 6. 
Therefore, the sum of X and Y would indeed be 6 + 0 = 6. 
2. Ans. Correct answer is 2 
Explanation 
 
3. Ans. Correct answer is 3 
Explanation 
 
 
Li does not form superoxide. 
 
K, Rb and Cs form stable super oxides but Cs has ionisation 
enthalpy less than 400 kJ. While K and Rb have ionisation 
enthalpy greater than 400 kJ mol
–1
. 
On the other hand, barium nitrate commonly crystallizes as an 
anhydrous salt, meaning it does not incorporate water molecules 
into its crystal structure. So, Y = 0. 
MCQ (Single Correct Answer) 
 
 
Q.1. Given below are two statements: One is labelled as Assertion 
A and the other is labelled as Reason R : 
 
Assertion (A): BeCl2 and MgCl2 produce characteristic flame 
 
Reason (R): The excitation energy is high in BeCl2 and MgCl2 
 
In the light of the above statements, choose the correct answer 
from the options given below : 
 
JEE Main 2023 (Online) 15th April Morning Shift 
 
Q.2. Better method for preparation of BeF2, among the following is 
 
Page 4


Physical World, Units and Measurements P-1
Numerical 
 
 
JEE Main 2023 (Online) 29th January Evening Shift 
 
 
 
JEE Main 2023 (Online) 11th April Evening Shift 
 
Q.2. The number of alkali metal(s), from Li,K,Cs, Rb having 
ionization enthalpy greater than  400 kJ mol
-1
 and forming stable 
super oxide is _________. 
 
Q.1.  Mg(NO3)2·XH2O and Ba(NO3)2·YH2O, represent formula of the 
crystalline forms of nitrate salts. Sum of X and Y is __________ 
JEE Main 2023 (Online) 31st January Evening Shift 
 
Q.3. On heating, LiNO3 gives how many compounds among the 
following __________ 
Answer Key & Explanation 
 
1. Ans. Correct answer is 6 
Explanation 
Magnesium nitrate typically crystallizes as a hexahydrate, which 
means it has six water molecules in its crystal structure. So, X = 6. 
Therefore, the sum of X and Y would indeed be 6 + 0 = 6. 
2. Ans. Correct answer is 2 
Explanation 
 
3. Ans. Correct answer is 3 
Explanation 
 
 
Li does not form superoxide. 
 
K, Rb and Cs form stable super oxides but Cs has ionisation 
enthalpy less than 400 kJ. While K and Rb have ionisation 
enthalpy greater than 400 kJ mol
–1
. 
On the other hand, barium nitrate commonly crystallizes as an 
anhydrous salt, meaning it does not incorporate water molecules 
into its crystal structure. So, Y = 0. 
MCQ (Single Correct Answer) 
 
 
Q.1. Given below are two statements: One is labelled as Assertion 
A and the other is labelled as Reason R : 
 
Assertion (A): BeCl2 and MgCl2 produce characteristic flame 
 
Reason (R): The excitation energy is high in BeCl2 and MgCl2 
 
In the light of the above statements, choose the correct answer 
from the options given below : 
 
JEE Main 2023 (Online) 15th April Morning Shift 
 
Q.2. Better method for preparation of BeF2, among the following is 
 
 
JEE Main 2023 (Online) 13th April Evening Shift 
 
Q.3. Identify the correct order of standard enthalpy of formation 
of sodium halides. 
 
JEE Main 2023 (Online) 13th April Evening Shift 
 
Q.4.  Be(OH)2 reacts with Sr(OH)2 to yield an ionic salt. 
Choose the incorrect option related to this reaction from the 
following: 
 
Page 5


Physical World, Units and Measurements P-1
Numerical 
 
 
JEE Main 2023 (Online) 29th January Evening Shift 
 
 
 
JEE Main 2023 (Online) 11th April Evening Shift 
 
Q.2. The number of alkali metal(s), from Li,K,Cs, Rb having 
ionization enthalpy greater than  400 kJ mol
-1
 and forming stable 
super oxide is _________. 
 
Q.1.  Mg(NO3)2·XH2O and Ba(NO3)2·YH2O, represent formula of the 
crystalline forms of nitrate salts. Sum of X and Y is __________ 
JEE Main 2023 (Online) 31st January Evening Shift 
 
Q.3. On heating, LiNO3 gives how many compounds among the 
following __________ 
Answer Key & Explanation 
 
1. Ans. Correct answer is 6 
Explanation 
Magnesium nitrate typically crystallizes as a hexahydrate, which 
means it has six water molecules in its crystal structure. So, X = 6. 
Therefore, the sum of X and Y would indeed be 6 + 0 = 6. 
2. Ans. Correct answer is 2 
Explanation 
 
3. Ans. Correct answer is 3 
Explanation 
 
 
Li does not form superoxide. 
 
K, Rb and Cs form stable super oxides but Cs has ionisation 
enthalpy less than 400 kJ. While K and Rb have ionisation 
enthalpy greater than 400 kJ mol
–1
. 
On the other hand, barium nitrate commonly crystallizes as an 
anhydrous salt, meaning it does not incorporate water molecules 
into its crystal structure. So, Y = 0. 
MCQ (Single Correct Answer) 
 
 
Q.1. Given below are two statements: One is labelled as Assertion 
A and the other is labelled as Reason R : 
 
Assertion (A): BeCl2 and MgCl2 produce characteristic flame 
 
Reason (R): The excitation energy is high in BeCl2 and MgCl2 
 
In the light of the above statements, choose the correct answer 
from the options given below : 
 
JEE Main 2023 (Online) 15th April Morning Shift 
 
Q.2. Better method for preparation of BeF2, among the following is 
 
 
JEE Main 2023 (Online) 13th April Evening Shift 
 
Q.3. Identify the correct order of standard enthalpy of formation 
of sodium halides. 
 
JEE Main 2023 (Online) 13th April Evening Shift 
 
Q.4.  Be(OH)2 reacts with Sr(OH)2 to yield an ionic salt. 
Choose the incorrect option related to this reaction from the 
following: 
 
 
JEE Main 2023 (Online) 13th April Morning Shift 
 
Q.5. The density of alkali metals is in the order 
 
JEE Main 2023 (Online) 12th April Morning Shift 
 
Q.6. In the given reaction cycle