Sample Question Paper 1: Chemistry, Class 11 | Chemistry for Grade 11 PDF Download

 Page 1


  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
CBSE  
CLASS – XI 
CHEMISTRY 
SAMPLE PAPER 1 
Time: 3 Hours  Marks: 70 
 
General Instructions 
? All questions are compulsory. 
? Section A: Q.no. 1 to 5 are very short answer questions and carry 1 mark each. 
? Section B: Q.no. 6 to 12 are short answer questions and carry 2 marks each. 
? Section C: Q.no. 13 to 24 are also short answer questions and carry 3 marks each. 
? Section D: Q.no. 25 to 27 are long answer questions and carry 5 marks each. 
? There is no overall choice. However an internal choice has been provided in two 
questions of one mark, two questions of two marks, four questions of three marks 
and all the three questions of five marks weightage. You have to attempt only one of 
the choices in such questions. 
? Use of log tables if necessary, use of calculators is not allowed. 
 
 
Section A 
 
1. Explain why o- nitrophenol has a lower boiling point than p – nitrophenol?   [1] 
 
OR 
 
Which of the two - 
--
2 2 2 3 2
O NCH CH O or  CH CH O is expected to be more stable and why?  
 
2. Out of
23
CO and BF , which one of them will have a larger bond angle and why?             [1] 
 
OR 
 
Why N2 is more stable than O2? Explain on the basis of molecular orbital theory. 
 
3. Is the eclipsed conformation of propane has the same or different energy as the eclipsed 
conformation of ethane?      [1] 
 
4. Due to which compound, ozone depletion is caused in Antarctica?   [1] 
 
5. Why are alkali metals used in photoelectric cells?                                                                       [1]  
 
 
  
Page 2


  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
CBSE  
CLASS – XI 
CHEMISTRY 
SAMPLE PAPER 1 
Time: 3 Hours  Marks: 70 
 
General Instructions 
? All questions are compulsory. 
? Section A: Q.no. 1 to 5 are very short answer questions and carry 1 mark each. 
? Section B: Q.no. 6 to 12 are short answer questions and carry 2 marks each. 
? Section C: Q.no. 13 to 24 are also short answer questions and carry 3 marks each. 
? Section D: Q.no. 25 to 27 are long answer questions and carry 5 marks each. 
? There is no overall choice. However an internal choice has been provided in two 
questions of one mark, two questions of two marks, four questions of three marks 
and all the three questions of five marks weightage. You have to attempt only one of 
the choices in such questions. 
? Use of log tables if necessary, use of calculators is not allowed. 
 
 
Section A 
 
1. Explain why o- nitrophenol has a lower boiling point than p – nitrophenol?   [1] 
 
OR 
 
Which of the two - 
--
2 2 2 3 2
O NCH CH O or  CH CH O is expected to be more stable and why?  
 
2. Out of
23
CO and BF , which one of them will have a larger bond angle and why?             [1] 
 
OR 
 
Why N2 is more stable than O2? Explain on the basis of molecular orbital theory. 
 
3. Is the eclipsed conformation of propane has the same or different energy as the eclipsed 
conformation of ethane?      [1] 
 
4. Due to which compound, ozone depletion is caused in Antarctica?   [1] 
 
5. Why are alkali metals used in photoelectric cells?                                                                       [1]  
 
 
  
  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
Section B 
 
6. Which of the following statements related to the modern periodic table is incorrect and 
why? [2] 
(a) Each block contains a number of columns equal to the number of electrons that 
can occupy that sub shell. 
(b)  The d - block has 8 columns, because a maximum 8 electrons can occupy all the 
orbitals in d - sub shell.           
     
7. All transition metals are d-block elements but all d-block elements are not transition 
metals. Explain.     [2] 
 
8. One of the spectral line of the caesium has a wavelength of 456 nm. Calculate the 
frequency of this line.      [2] 
 
9. PbO andPbO2 react with HCl according to the following reactions:     [2] 
       2PbO + 4HCl ? 2PbCl2 + 2H2O 
        PbO2 + 4HCl ? PbCl2 + Cl2 + 2H2O   
Why do these compounds differ in their reactivity? 
 
10. Consider the reaction of water with F2 and suggest, in terms of oxidation and       
reduction, which species are oxidized/ reduced.            [2] 
  
  OR 
Complete the following reactions: 
(a) PbS(g) + H2O2(aq)   ?  
(b) CO(g) + 2 H2(g) 
Cobalt
catalyst
? ? ? ?  
 
11. Why do magnesium and beryllium not impart colour to the flame in the flame test?    [2] 
 
12. Calculate the mass percent of different elements in sodium sulphate,(Na2SO4)            [2] 
 
OR 
 
How much copper can be obtained from 100 g of copper sulphate (CuSO4)? 
(Atomic mass of Cu – 63.5 amu) 
 
  
Page 3


  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
CBSE  
CLASS – XI 
CHEMISTRY 
SAMPLE PAPER 1 
Time: 3 Hours  Marks: 70 
 
General Instructions 
? All questions are compulsory. 
? Section A: Q.no. 1 to 5 are very short answer questions and carry 1 mark each. 
? Section B: Q.no. 6 to 12 are short answer questions and carry 2 marks each. 
? Section C: Q.no. 13 to 24 are also short answer questions and carry 3 marks each. 
? Section D: Q.no. 25 to 27 are long answer questions and carry 5 marks each. 
? There is no overall choice. However an internal choice has been provided in two 
questions of one mark, two questions of two marks, four questions of three marks 
and all the three questions of five marks weightage. You have to attempt only one of 
the choices in such questions. 
? Use of log tables if necessary, use of calculators is not allowed. 
 
 
Section A 
 
1. Explain why o- nitrophenol has a lower boiling point than p – nitrophenol?   [1] 
 
OR 
 
Which of the two - 
--
2 2 2 3 2
O NCH CH O or  CH CH O is expected to be more stable and why?  
 
2. Out of
23
CO and BF , which one of them will have a larger bond angle and why?             [1] 
 
OR 
 
Why N2 is more stable than O2? Explain on the basis of molecular orbital theory. 
 
3. Is the eclipsed conformation of propane has the same or different energy as the eclipsed 
conformation of ethane?      [1] 
 
4. Due to which compound, ozone depletion is caused in Antarctica?   [1] 
 
5. Why are alkali metals used in photoelectric cells?                                                                       [1]  
 
 
  
  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
Section B 
 
6. Which of the following statements related to the modern periodic table is incorrect and 
why? [2] 
(a) Each block contains a number of columns equal to the number of electrons that 
can occupy that sub shell. 
(b)  The d - block has 8 columns, because a maximum 8 electrons can occupy all the 
orbitals in d - sub shell.           
     
7. All transition metals are d-block elements but all d-block elements are not transition 
metals. Explain.     [2] 
 
8. One of the spectral line of the caesium has a wavelength of 456 nm. Calculate the 
frequency of this line.      [2] 
 
9. PbO andPbO2 react with HCl according to the following reactions:     [2] 
       2PbO + 4HCl ? 2PbCl2 + 2H2O 
        PbO2 + 4HCl ? PbCl2 + Cl2 + 2H2O   
Why do these compounds differ in their reactivity? 
 
10. Consider the reaction of water with F2 and suggest, in terms of oxidation and       
reduction, which species are oxidized/ reduced.            [2] 
  
  OR 
Complete the following reactions: 
(a) PbS(g) + H2O2(aq)   ?  
(b) CO(g) + 2 H2(g) 
Cobalt
catalyst
? ? ? ?  
 
11. Why do magnesium and beryllium not impart colour to the flame in the flame test?    [2] 
 
12. Calculate the mass percent of different elements in sodium sulphate,(Na2SO4)            [2] 
 
OR 
 
How much copper can be obtained from 100 g of copper sulphate (CuSO4)? 
(Atomic mass of Cu – 63.5 amu) 
 
  
  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
Section C 
 
13.                            [3] 
(a) The 4f sub shell of an atom contains 12 electrons. What is the maximum number of 
electrons having the same spin in it?        
(b) Explain the meaning of 4p6. 
(c) Write the electronic configuration of the atom with atomic number 29 
 
OR 
 
(a) Calculate the total number of electrons present in one mole of methane. 
(b) An atomic orbital has n = 3. What are the possible values of l and ?
l
m    
 
14. Explain the hybridisation of
4
SF ?             [3]  
 
OR 
 
(a) Although both CO2 and H2O are triatomic molecules, the shape of H2O molecule is 
bent while that of CO2 is linear. Explain on the basis of dipole moment. 
(b) Write the significance of dipole moment. 
 
 
15. The drain cleaner contains small bits of aluminium which react with caustic soda to 
produce dihydrogen gas.  What volume of dihydrogen at 20°C and one bar pressure 
will be released when 0.15 g of aluminium reacts.             [3]  
 
16.  
(a) What is spontaneous process?                     [3] 
(b) Predict in which of the following, entropy increases/decreases. 
i) A liquid crystallises into a solid. 
ii) Temperature of crystallise solid is raised from 0 K to 115 K 
iii) 2NaHCO3(s) ? Na2CO3 +CO2(g) + H2O(g) 
iv) H2(g) ? 2H(g) 
 
17.  
(a) Write the expression for equilibrium constant for the reaction:         [3]  
                             
? ? ? ? ? ?
22 g s g
H +I 2HI
 
(b) Calculate the pH of a buffer solution containing 0.2 mole of NH4Cl and 0.1 mole of    
NH4OH per litre. (Given Kb for NH4OH = 1.85 X 10
-5
)
 
 
OR  
Page 4


  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
CBSE  
CLASS – XI 
CHEMISTRY 
SAMPLE PAPER 1 
Time: 3 Hours  Marks: 70 
 
General Instructions 
? All questions are compulsory. 
? Section A: Q.no. 1 to 5 are very short answer questions and carry 1 mark each. 
? Section B: Q.no. 6 to 12 are short answer questions and carry 2 marks each. 
? Section C: Q.no. 13 to 24 are also short answer questions and carry 3 marks each. 
? Section D: Q.no. 25 to 27 are long answer questions and carry 5 marks each. 
? There is no overall choice. However an internal choice has been provided in two 
questions of one mark, two questions of two marks, four questions of three marks 
and all the three questions of five marks weightage. You have to attempt only one of 
the choices in such questions. 
? Use of log tables if necessary, use of calculators is not allowed. 
 
 
Section A 
 
1. Explain why o- nitrophenol has a lower boiling point than p – nitrophenol?   [1] 
 
OR 
 
Which of the two - 
--
2 2 2 3 2
O NCH CH O or  CH CH O is expected to be more stable and why?  
 
2. Out of
23
CO and BF , which one of them will have a larger bond angle and why?             [1] 
 
OR 
 
Why N2 is more stable than O2? Explain on the basis of molecular orbital theory. 
 
3. Is the eclipsed conformation of propane has the same or different energy as the eclipsed 
conformation of ethane?      [1] 
 
4. Due to which compound, ozone depletion is caused in Antarctica?   [1] 
 
5. Why are alkali metals used in photoelectric cells?                                                                       [1]  
 
 
  
  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
Section B 
 
6. Which of the following statements related to the modern periodic table is incorrect and 
why? [2] 
(a) Each block contains a number of columns equal to the number of electrons that 
can occupy that sub shell. 
(b)  The d - block has 8 columns, because a maximum 8 electrons can occupy all the 
orbitals in d - sub shell.           
     
7. All transition metals are d-block elements but all d-block elements are not transition 
metals. Explain.     [2] 
 
8. One of the spectral line of the caesium has a wavelength of 456 nm. Calculate the 
frequency of this line.      [2] 
 
9. PbO andPbO2 react with HCl according to the following reactions:     [2] 
       2PbO + 4HCl ? 2PbCl2 + 2H2O 
        PbO2 + 4HCl ? PbCl2 + Cl2 + 2H2O   
Why do these compounds differ in their reactivity? 
 
10. Consider the reaction of water with F2 and suggest, in terms of oxidation and       
reduction, which species are oxidized/ reduced.            [2] 
  
  OR 
Complete the following reactions: 
(a) PbS(g) + H2O2(aq)   ?  
(b) CO(g) + 2 H2(g) 
Cobalt
catalyst
? ? ? ?  
 
11. Why do magnesium and beryllium not impart colour to the flame in the flame test?    [2] 
 
12. Calculate the mass percent of different elements in sodium sulphate,(Na2SO4)            [2] 
 
OR 
 
How much copper can be obtained from 100 g of copper sulphate (CuSO4)? 
(Atomic mass of Cu – 63.5 amu) 
 
  
  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
Section C 
 
13.                            [3] 
(a) The 4f sub shell of an atom contains 12 electrons. What is the maximum number of 
electrons having the same spin in it?        
(b) Explain the meaning of 4p6. 
(c) Write the electronic configuration of the atom with atomic number 29 
 
OR 
 
(a) Calculate the total number of electrons present in one mole of methane. 
(b) An atomic orbital has n = 3. What are the possible values of l and ?
l
m    
 
14. Explain the hybridisation of
4
SF ?             [3]  
 
OR 
 
(a) Although both CO2 and H2O are triatomic molecules, the shape of H2O molecule is 
bent while that of CO2 is linear. Explain on the basis of dipole moment. 
(b) Write the significance of dipole moment. 
 
 
15. The drain cleaner contains small bits of aluminium which react with caustic soda to 
produce dihydrogen gas.  What volume of dihydrogen at 20°C and one bar pressure 
will be released when 0.15 g of aluminium reacts.             [3]  
 
16.  
(a) What is spontaneous process?                     [3] 
(b) Predict in which of the following, entropy increases/decreases. 
i) A liquid crystallises into a solid. 
ii) Temperature of crystallise solid is raised from 0 K to 115 K 
iii) 2NaHCO3(s) ? Na2CO3 +CO2(g) + H2O(g) 
iv) H2(g) ? 2H(g) 
 
17.  
(a) Write the expression for equilibrium constant for the reaction:         [3]  
                             
? ? ? ? ? ?
22 g s g
H +I 2HI
 
(b) Calculate the pH of a buffer solution containing 0.2 mole of NH4Cl and 0.1 mole of    
NH4OH per litre. (Given Kb for NH4OH = 1.85 X 10
-5
)
 
 
OR  
  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
Consider the reaction:          
? ? ? ? ? ?
2 2 3
2SO g +O g 2SO g +189.4kJ .  
Indicate the direction in which the equilibrium with shift when:  
(a) Temperature is increased 
(b) Pressure is increased 
(c) Concentration of 
2
SO is increase 
 
18. Balance ? ? ? ?
3 3 4 2 2
P + HNO H PO + NO +H O by oxidation number method. [3] 
   
OR 
 
Write the half reactions for each of the following redox reactions: 
          
? ?
? ?
? ? ? ? ? ?
? ? ? ?
) aq (
s 2 aq s ( ) ( ) ( ) ( )
2
2 aq a
2 aq
q aq
( ) 2gs
3
s
a      Zn PbCl Pb   ZnCl
b      2Fe 2I I 2Fe
(c) 2Na Cl 2NaCl
???
?
?
??
??
?
?
 
 
19. What do you understand by the term ‘non-stoichiometric hydrides? Do you expect this 
this type of hydrides to be formed by alkali metals? Justify.            [3] 
 
20.                                             [3] 
 
(a)  
             
 
(b)  
                      
(c)  
                      
 
Page 5


  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
CBSE  
CLASS – XI 
CHEMISTRY 
SAMPLE PAPER 1 
Time: 3 Hours  Marks: 70 
 
General Instructions 
? All questions are compulsory. 
? Section A: Q.no. 1 to 5 are very short answer questions and carry 1 mark each. 
? Section B: Q.no. 6 to 12 are short answer questions and carry 2 marks each. 
? Section C: Q.no. 13 to 24 are also short answer questions and carry 3 marks each. 
? Section D: Q.no. 25 to 27 are long answer questions and carry 5 marks each. 
? There is no overall choice. However an internal choice has been provided in two 
questions of one mark, two questions of two marks, four questions of three marks 
and all the three questions of five marks weightage. You have to attempt only one of 
the choices in such questions. 
? Use of log tables if necessary, use of calculators is not allowed. 
 
 
Section A 
 
1. Explain why o- nitrophenol has a lower boiling point than p – nitrophenol?   [1] 
 
OR 
 
Which of the two - 
--
2 2 2 3 2
O NCH CH O or  CH CH O is expected to be more stable and why?  
 
2. Out of
23
CO and BF , which one of them will have a larger bond angle and why?             [1] 
 
OR 
 
Why N2 is more stable than O2? Explain on the basis of molecular orbital theory. 
 
3. Is the eclipsed conformation of propane has the same or different energy as the eclipsed 
conformation of ethane?      [1] 
 
4. Due to which compound, ozone depletion is caused in Antarctica?   [1] 
 
5. Why are alkali metals used in photoelectric cells?                                                                       [1]  
 
 
  
  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
Section B 
 
6. Which of the following statements related to the modern periodic table is incorrect and 
why? [2] 
(a) Each block contains a number of columns equal to the number of electrons that 
can occupy that sub shell. 
(b)  The d - block has 8 columns, because a maximum 8 electrons can occupy all the 
orbitals in d - sub shell.           
     
7. All transition metals are d-block elements but all d-block elements are not transition 
metals. Explain.     [2] 
 
8. One of the spectral line of the caesium has a wavelength of 456 nm. Calculate the 
frequency of this line.      [2] 
 
9. PbO andPbO2 react with HCl according to the following reactions:     [2] 
       2PbO + 4HCl ? 2PbCl2 + 2H2O 
        PbO2 + 4HCl ? PbCl2 + Cl2 + 2H2O   
Why do these compounds differ in their reactivity? 
 
10. Consider the reaction of water with F2 and suggest, in terms of oxidation and       
reduction, which species are oxidized/ reduced.            [2] 
  
  OR 
Complete the following reactions: 
(a) PbS(g) + H2O2(aq)   ?  
(b) CO(g) + 2 H2(g) 
Cobalt
catalyst
? ? ? ?  
 
11. Why do magnesium and beryllium not impart colour to the flame in the flame test?    [2] 
 
12. Calculate the mass percent of different elements in sodium sulphate,(Na2SO4)            [2] 
 
OR 
 
How much copper can be obtained from 100 g of copper sulphate (CuSO4)? 
(Atomic mass of Cu – 63.5 amu) 
 
  
  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
Section C 
 
13.                            [3] 
(a) The 4f sub shell of an atom contains 12 electrons. What is the maximum number of 
electrons having the same spin in it?        
(b) Explain the meaning of 4p6. 
(c) Write the electronic configuration of the atom with atomic number 29 
 
OR 
 
(a) Calculate the total number of electrons present in one mole of methane. 
(b) An atomic orbital has n = 3. What are the possible values of l and ?
l
m    
 
14. Explain the hybridisation of
4
SF ?             [3]  
 
OR 
 
(a) Although both CO2 and H2O are triatomic molecules, the shape of H2O molecule is 
bent while that of CO2 is linear. Explain on the basis of dipole moment. 
(b) Write the significance of dipole moment. 
 
 
15. The drain cleaner contains small bits of aluminium which react with caustic soda to 
produce dihydrogen gas.  What volume of dihydrogen at 20°C and one bar pressure 
will be released when 0.15 g of aluminium reacts.             [3]  
 
16.  
(a) What is spontaneous process?                     [3] 
(b) Predict in which of the following, entropy increases/decreases. 
i) A liquid crystallises into a solid. 
ii) Temperature of crystallise solid is raised from 0 K to 115 K 
iii) 2NaHCO3(s) ? Na2CO3 +CO2(g) + H2O(g) 
iv) H2(g) ? 2H(g) 
 
17.  
(a) Write the expression for equilibrium constant for the reaction:         [3]  
                             
? ? ? ? ? ?
22 g s g
H +I 2HI
 
(b) Calculate the pH of a buffer solution containing 0.2 mole of NH4Cl and 0.1 mole of    
NH4OH per litre. (Given Kb for NH4OH = 1.85 X 10
-5
)
 
 
OR  
  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
Consider the reaction:          
? ? ? ? ? ?
2 2 3
2SO g +O g 2SO g +189.4kJ .  
Indicate the direction in which the equilibrium with shift when:  
(a) Temperature is increased 
(b) Pressure is increased 
(c) Concentration of 
2
SO is increase 
 
18. Balance ? ? ? ?
3 3 4 2 2
P + HNO H PO + NO +H O by oxidation number method. [3] 
   
OR 
 
Write the half reactions for each of the following redox reactions: 
          
? ?
? ?
? ? ? ? ? ?
? ? ? ?
) aq (
s 2 aq s ( ) ( ) ( ) ( )
2
2 aq a
2 aq
q aq
( ) 2gs
3
s
a      Zn PbCl Pb   ZnCl
b      2Fe 2I I 2Fe
(c) 2Na Cl 2NaCl
???
?
?
??
??
?
?
 
 
19. What do you understand by the term ‘non-stoichiometric hydrides? Do you expect this 
this type of hydrides to be formed by alkali metals? Justify.            [3] 
 
20.                                             [3] 
 
(a)  
             
 
(b)  
                      
(c)  
                      
 
  
 
CBSE XI | Chemistry 
Sample Paper – 1 
 
    
 
21.                 [3] 
(a) Arrange the following carbanions in the increasing order of their stability  
     
? ? ? ? 3,
3 3 2 3
32
CH C, CH CH , CH CH CH
? ? ? ?
  
(b) What is the hybridisation of the negatively charged carbon atom in a carbanion? 
 
22. Explain.            [3] 
(a) Alkali metals are prepared by electrolysis of their fused chlorides. 
(b) Why are lithium salts commonly hydrated and those of other alkali metal ions 
usually anhydrous? 
 
23. Calculate the molarity of a solution of ethanol in water in which the mole fraction of 
ethanol is 0.040.          [3] 
 
24. Complete the following chemical equations:       [3] 
(a) Z + 3LiAlH4 ? X + 3LiF + 3AlF3 
(b) X + 6H2O ? Y + 6H2 
(c) 3X + 3O2 
?
? ? ? B2O + 3H2O 
 
 
 
Section D 
 
 
25. For the reaction                  [5] 
? ? ? ? ? ? ? ? ? ?
43
NH Cl s NH g + HCl g  
At 25°C, enthalpy change,
-1
? H = + 1 7 7 k J m o l       
Entropy change 
-1 -1
? S = + 2 8 5 J K m o l .  
Calculate free energy change 
o
? G a t 2 5 C and predict whether the reaction is 
spontaneous or not.   
OR 
 
Calculate the enthalpy of formation of benzene, using the following data 
 
 
? ? ? ? ? ? ? ?
? ? ? ? ? ?
? ? ? ? ? ?
?
6 6 2 2 2 g g l
?
2 2 f s g g
?
2 2 2 f g g l
C
15
C H + O 6CO +3H O ? H = - 3 2 6 6 . 0 k J
2
C +O CO ? H = - 3 9 3 . 1 k J
1
H + O H O ? H = - 2 8 6 . 0 k J
2
? ? ?
? ? ?
? ? ?
l