CBSE Chemistry Past year paper - 2014, Class 12 | Additional Study Material for NEET PDF Download

 Page 1


  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
CBSE  
Class XII Chemistry (Theory) 
Board Question Paper 2014 – Set 1 
Time: 3 hrs Max. Marks: 70 
 
General Instructions: 
 
(i) All questions are compulsory. 
(ii) Questions  number  1  to  8  are  very  short-answer  questions  and  carry  
1 mark each. 
(iii) Questions number 9 to 18 are short-answer questions and carry 2 marks each 
(iv) Questions  number  19 to 27  are  also  short-answer questions and carry 
03 marks each. 
(v) Question number 28 to 30 are long-answer questions and carry 5 marks each. 
Use Log Tables, if necessary. Use of calculators is not allowed 
  
 
1.  What is the effect of temperature on chemisorption?                   (1) 
 
2.  What is the role of zinc metal in the extraction of silver?           (1) 
 
3. What is the basicity of H3PO3?               (1) 
 
4. Identify the chiral molecule in the following pair :            (1) 
                 
 
5. Which of the following is a natural polymer?             (1) 
Buna-S, Proteins,   PVC 
 
6. The  conversion  of  primary   aromatic   amines   into  diazonium   salts    
is known as                 (1) 
 
7. What are the products of hydrolysis of sucrose?             (1) 
 
8. Write the structure of p-methylbenzaldehyde.             (1) 
 
9. An element  with  density  2.8 g cm
-3
  forms  a  f.c.c. unit  cell with  edge  
length 4 × l0
-8
 cm. Calculate the molar mass of the element. 
(Given :NA=6.022 × 10
23
 mol
-1
)              (2) 
 
10. (i) What  type of non-stoichiometric point defect is responsible  for  
the pink colour of LiCl? 
(ii) What type of stoichiometric defect is shown by NaCl?           (2) 
Page 2


  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
CBSE  
Class XII Chemistry (Theory) 
Board Question Paper 2014 – Set 1 
Time: 3 hrs Max. Marks: 70 
 
General Instructions: 
 
(i) All questions are compulsory. 
(ii) Questions  number  1  to  8  are  very  short-answer  questions  and  carry  
1 mark each. 
(iii) Questions number 9 to 18 are short-answer questions and carry 2 marks each 
(iv) Questions  number  19 to 27  are  also  short-answer questions and carry 
03 marks each. 
(v) Question number 28 to 30 are long-answer questions and carry 5 marks each. 
Use Log Tables, if necessary. Use of calculators is not allowed 
  
 
1.  What is the effect of temperature on chemisorption?                   (1) 
 
2.  What is the role of zinc metal in the extraction of silver?           (1) 
 
3. What is the basicity of H3PO3?               (1) 
 
4. Identify the chiral molecule in the following pair :            (1) 
                 
 
5. Which of the following is a natural polymer?             (1) 
Buna-S, Proteins,   PVC 
 
6. The  conversion  of  primary   aromatic   amines   into  diazonium   salts    
is known as                 (1) 
 
7. What are the products of hydrolysis of sucrose?             (1) 
 
8. Write the structure of p-methylbenzaldehyde.             (1) 
 
9. An element  with  density  2.8 g cm
-3
  forms  a  f.c.c. unit  cell with  edge  
length 4 × l0
-8
 cm. Calculate the molar mass of the element. 
(Given :NA=6.022 × 10
23
 mol
-1
)              (2) 
 
10. (i) What  type of non-stoichiometric point defect is responsible  for  
the pink colour of LiCl? 
(ii) What type of stoichiometric defect is shown by NaCl?           (2) 
  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
OR 
 
How will you distinguish between the following pairs of terms:            
(i)     Tetrahedral and octahedral voids 
(ii)  Crystal lattice and unit cell               (2) 
 
11. State Kohlrausch law of independent migration of ions.  Why does the  
conductivity of a solution decrease with dilution?            (2) 
 
12. For a chemical reaction R            P, the variation in the concentration (R) vs. 
 
time (t) plot is given as               (2) 
 
(i) Predict the order of the reaction.  
(ii) What is the slope of the curve? 
 
13. Explain the principle of the method of electrolytic refining of metals.  
Give one example.                 (2) 
 
14. Complete the following equations :               (2) 
(i) P4 + H2O          
(ii)  XeF4 + O2F2             
 
15. Draw the structures of the following :                (2)         
(i) XeF2 
(ii) BrF3 
 
16. Write the equations involved in the following reactions:            (2) 
(i) Reimer - Tiemann reaction 
(ii)  Williamson synthesis 
 
17. Write the mechanism of the following reaction:             (2) 
 
HBr
3 2 3 2 2
CH CH OH CH CH Br+H O ? ? ? 
  
Page 3


  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
CBSE  
Class XII Chemistry (Theory) 
Board Question Paper 2014 – Set 1 
Time: 3 hrs Max. Marks: 70 
 
General Instructions: 
 
(i) All questions are compulsory. 
(ii) Questions  number  1  to  8  are  very  short-answer  questions  and  carry  
1 mark each. 
(iii) Questions number 9 to 18 are short-answer questions and carry 2 marks each 
(iv) Questions  number  19 to 27  are  also  short-answer questions and carry 
03 marks each. 
(v) Question number 28 to 30 are long-answer questions and carry 5 marks each. 
Use Log Tables, if necessary. Use of calculators is not allowed 
  
 
1.  What is the effect of temperature on chemisorption?                   (1) 
 
2.  What is the role of zinc metal in the extraction of silver?           (1) 
 
3. What is the basicity of H3PO3?               (1) 
 
4. Identify the chiral molecule in the following pair :            (1) 
                 
 
5. Which of the following is a natural polymer?             (1) 
Buna-S, Proteins,   PVC 
 
6. The  conversion  of  primary   aromatic   amines   into  diazonium   salts    
is known as                 (1) 
 
7. What are the products of hydrolysis of sucrose?             (1) 
 
8. Write the structure of p-methylbenzaldehyde.             (1) 
 
9. An element  with  density  2.8 g cm
-3
  forms  a  f.c.c. unit  cell with  edge  
length 4 × l0
-8
 cm. Calculate the molar mass of the element. 
(Given :NA=6.022 × 10
23
 mol
-1
)              (2) 
 
10. (i) What  type of non-stoichiometric point defect is responsible  for  
the pink colour of LiCl? 
(ii) What type of stoichiometric defect is shown by NaCl?           (2) 
  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
OR 
 
How will you distinguish between the following pairs of terms:            
(i)     Tetrahedral and octahedral voids 
(ii)  Crystal lattice and unit cell               (2) 
 
11. State Kohlrausch law of independent migration of ions.  Why does the  
conductivity of a solution decrease with dilution?            (2) 
 
12. For a chemical reaction R            P, the variation in the concentration (R) vs. 
 
time (t) plot is given as               (2) 
 
(i) Predict the order of the reaction.  
(ii) What is the slope of the curve? 
 
13. Explain the principle of the method of electrolytic refining of metals.  
Give one example.                 (2) 
 
14. Complete the following equations :               (2) 
(i) P4 + H2O          
(ii)  XeF4 + O2F2             
 
15. Draw the structures of the following :                (2)         
(i) XeF2 
(ii) BrF3 
 
16. Write the equations involved in the following reactions:            (2) 
(i) Reimer - Tiemann reaction 
(ii)  Williamson synthesis 
 
17. Write the mechanism of the following reaction:             (2) 
 
HBr
3 2 3 2 2
CH CH OH CH CH Br+H O ? ? ? 
  
  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
18. Write the name of monomers used for getting the following polymers:         (2) 
(i) Bakelite 
(ii)  Neoprene 
 
19. (a)  Calculate ?rG
O
  for the reaction 
Mg (s) + Cu
2+
 (aq)   Mg 
2+
 (aq) + Cu (s) 
    
Given: E
0
 cell= + 2.71 V,   1 F = 96500 C mol
-1
 
 
(b)  Name the type of cell which was used in Apollo space programme 
 for providing electrical power.              (3) 
 
20. The   following   data    were   obtained during the   first   order   thermal 
decomposition of SO2Cl2 at a constant volume: 
        
2 2(g) 2 (g) 2(g)
SO Cl SO +Cl ? 
 
Experiment Time/s
-1
 Total pressure/atm 
1 0 0.4 
2 100 0.7 
 
Calculate the rate constant.               (3) 
               (Given: log 4 = 0.6021, log 2 = 0.3010 
 
21. What are emulsions? What are their different types? Give one example  
of each type.                        (3)  
22. Give reasons for the following:              (3) 
(i)  (CH3)3 P = O exists but (CH3)3 N = O does not. 
(ii)  Oxygen has less electron gain enthalpy with negative sign than sulphur. 
(iii)  H3PO2 is a stronger reducing agent than HaPO3. 
 
23. (i) Write the IUPAC name of the complex [Cr(NH3)4 Cl2]Cl. 
(ii) What type of isomerism is exhibited by the complex [Co (en) 3]
3+
? 
(en= ethane-1,2-diamine) 
  (iii) Why is [NiCl4]
2-
 paramagnetic but [Ni (CO)4] is diamagnetic? 
   (At. nos. : Cr = 24, Co = 27, Ni = 28)              (3) 
 
24. (a) Draw  the  structures of major  monohalo products  in  each  of the 
 following reactions: 
i) 
                   
 
 
Page 4


  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
CBSE  
Class XII Chemistry (Theory) 
Board Question Paper 2014 – Set 1 
Time: 3 hrs Max. Marks: 70 
 
General Instructions: 
 
(i) All questions are compulsory. 
(ii) Questions  number  1  to  8  are  very  short-answer  questions  and  carry  
1 mark each. 
(iii) Questions number 9 to 18 are short-answer questions and carry 2 marks each 
(iv) Questions  number  19 to 27  are  also  short-answer questions and carry 
03 marks each. 
(v) Question number 28 to 30 are long-answer questions and carry 5 marks each. 
Use Log Tables, if necessary. Use of calculators is not allowed 
  
 
1.  What is the effect of temperature on chemisorption?                   (1) 
 
2.  What is the role of zinc metal in the extraction of silver?           (1) 
 
3. What is the basicity of H3PO3?               (1) 
 
4. Identify the chiral molecule in the following pair :            (1) 
                 
 
5. Which of the following is a natural polymer?             (1) 
Buna-S, Proteins,   PVC 
 
6. The  conversion  of  primary   aromatic   amines   into  diazonium   salts    
is known as                 (1) 
 
7. What are the products of hydrolysis of sucrose?             (1) 
 
8. Write the structure of p-methylbenzaldehyde.             (1) 
 
9. An element  with  density  2.8 g cm
-3
  forms  a  f.c.c. unit  cell with  edge  
length 4 × l0
-8
 cm. Calculate the molar mass of the element. 
(Given :NA=6.022 × 10
23
 mol
-1
)              (2) 
 
10. (i) What  type of non-stoichiometric point defect is responsible  for  
the pink colour of LiCl? 
(ii) What type of stoichiometric defect is shown by NaCl?           (2) 
  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
OR 
 
How will you distinguish between the following pairs of terms:            
(i)     Tetrahedral and octahedral voids 
(ii)  Crystal lattice and unit cell               (2) 
 
11. State Kohlrausch law of independent migration of ions.  Why does the  
conductivity of a solution decrease with dilution?            (2) 
 
12. For a chemical reaction R            P, the variation in the concentration (R) vs. 
 
time (t) plot is given as               (2) 
 
(i) Predict the order of the reaction.  
(ii) What is the slope of the curve? 
 
13. Explain the principle of the method of electrolytic refining of metals.  
Give one example.                 (2) 
 
14. Complete the following equations :               (2) 
(i) P4 + H2O          
(ii)  XeF4 + O2F2             
 
15. Draw the structures of the following :                (2)         
(i) XeF2 
(ii) BrF3 
 
16. Write the equations involved in the following reactions:            (2) 
(i) Reimer - Tiemann reaction 
(ii)  Williamson synthesis 
 
17. Write the mechanism of the following reaction:             (2) 
 
HBr
3 2 3 2 2
CH CH OH CH CH Br+H O ? ? ? 
  
  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
18. Write the name of monomers used for getting the following polymers:         (2) 
(i) Bakelite 
(ii)  Neoprene 
 
19. (a)  Calculate ?rG
O
  for the reaction 
Mg (s) + Cu
2+
 (aq)   Mg 
2+
 (aq) + Cu (s) 
    
Given: E
0
 cell= + 2.71 V,   1 F = 96500 C mol
-1
 
 
(b)  Name the type of cell which was used in Apollo space programme 
 for providing electrical power.              (3) 
 
20. The   following   data    were   obtained during the   first   order   thermal 
decomposition of SO2Cl2 at a constant volume: 
        
2 2(g) 2 (g) 2(g)
SO Cl SO +Cl ? 
 
Experiment Time/s
-1
 Total pressure/atm 
1 0 0.4 
2 100 0.7 
 
Calculate the rate constant.               (3) 
               (Given: log 4 = 0.6021, log 2 = 0.3010 
 
21. What are emulsions? What are their different types? Give one example  
of each type.                        (3)  
22. Give reasons for the following:              (3) 
(i)  (CH3)3 P = O exists but (CH3)3 N = O does not. 
(ii)  Oxygen has less electron gain enthalpy with negative sign than sulphur. 
(iii)  H3PO2 is a stronger reducing agent than HaPO3. 
 
23. (i) Write the IUPAC name of the complex [Cr(NH3)4 Cl2]Cl. 
(ii) What type of isomerism is exhibited by the complex [Co (en) 3]
3+
? 
(en= ethane-1,2-diamine) 
  (iii) Why is [NiCl4]
2-
 paramagnetic but [Ni (CO)4] is diamagnetic? 
   (At. nos. : Cr = 24, Co = 27, Ni = 28)              (3) 
 
24. (a) Draw  the  structures of major  monohalo products  in  each  of the 
 following reactions: 
i) 
                   
 
 
  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
ii) 
      
 
(b) Which halogen compound in oach of the following pairs  will react faster  in 
SN2 reaction : 
(i) CH3Br or  CH3I 
(ii) (CH3)3 C- Cl or  CH3 -  Cl 
 
25. Account for the following:                (3) 
(i)  Primary amines (R-NH2) have higher boiling point than tertiary 
 amines (R3N). 
(ii) Aniline does not undergo Friedel - Crafts reaction. 
(iii)  (CH3)2NH  is more basic than  (CH3)3N in an aqueous solution. 
 
OR 
 
Give the structures of A, B and C in the following reactions: 
(i) 
22
NaNO +HCl H O Sn+HCl
6 5 2 273K
C H NO A B C ? ? ? ? ? ? ? ? ? ? ? ? 
(ii) 
+
3 22
NH H O/H Br +KOH
3
CH CN A B C
?
? ? ? ? ? ? ? ? ? ? ? 
 
26. Define the following terms as related to proteins:            (3) 
(i) Peptide linkage 
(ii) Primary structure 
(iii)  Denaturation 
 
27. On the occasion of World Health Day, Dr. Satpal organized a 'health camp' for the 
poor farmers living in a nearby village.  After check-up,   he was shocked to see that 
most of the farmers suffered from cancer due to regular exposure to pesticides and   
many   wore diabetic.  They   distributed free medicines to them.  Dr.  Satpal 
immodiately reported the   matter to the National Human Rights   Commission 
(NHRC).  On the suggestions of NHRC, the government decided to provide medical     
care,   financial assistance, setting up of super-specialty hospitals for treatment  
and prevention of the deadly disease  in the affected villages  all over India. 
(i) Write the values shown by 
(a)  Dr. Satpal 
(b)  NHRC. 
 
 (ii)  What type of analgesics are chiefly used for the relief of pains of 
terminal cancer? 
(iii)  Give an example of artificial sweetener that could have   been  
recommended to diabetic patients.             (3) 
  
Page 5


  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
CBSE  
Class XII Chemistry (Theory) 
Board Question Paper 2014 – Set 1 
Time: 3 hrs Max. Marks: 70 
 
General Instructions: 
 
(i) All questions are compulsory. 
(ii) Questions  number  1  to  8  are  very  short-answer  questions  and  carry  
1 mark each. 
(iii) Questions number 9 to 18 are short-answer questions and carry 2 marks each 
(iv) Questions  number  19 to 27  are  also  short-answer questions and carry 
03 marks each. 
(v) Question number 28 to 30 are long-answer questions and carry 5 marks each. 
Use Log Tables, if necessary. Use of calculators is not allowed 
  
 
1.  What is the effect of temperature on chemisorption?                   (1) 
 
2.  What is the role of zinc metal in the extraction of silver?           (1) 
 
3. What is the basicity of H3PO3?               (1) 
 
4. Identify the chiral molecule in the following pair :            (1) 
                 
 
5. Which of the following is a natural polymer?             (1) 
Buna-S, Proteins,   PVC 
 
6. The  conversion  of  primary   aromatic   amines   into  diazonium   salts    
is known as                 (1) 
 
7. What are the products of hydrolysis of sucrose?             (1) 
 
8. Write the structure of p-methylbenzaldehyde.             (1) 
 
9. An element  with  density  2.8 g cm
-3
  forms  a  f.c.c. unit  cell with  edge  
length 4 × l0
-8
 cm. Calculate the molar mass of the element. 
(Given :NA=6.022 × 10
23
 mol
-1
)              (2) 
 
10. (i) What  type of non-stoichiometric point defect is responsible  for  
the pink colour of LiCl? 
(ii) What type of stoichiometric defect is shown by NaCl?           (2) 
  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
OR 
 
How will you distinguish between the following pairs of terms:            
(i)     Tetrahedral and octahedral voids 
(ii)  Crystal lattice and unit cell               (2) 
 
11. State Kohlrausch law of independent migration of ions.  Why does the  
conductivity of a solution decrease with dilution?            (2) 
 
12. For a chemical reaction R            P, the variation in the concentration (R) vs. 
 
time (t) plot is given as               (2) 
 
(i) Predict the order of the reaction.  
(ii) What is the slope of the curve? 
 
13. Explain the principle of the method of electrolytic refining of metals.  
Give one example.                 (2) 
 
14. Complete the following equations :               (2) 
(i) P4 + H2O          
(ii)  XeF4 + O2F2             
 
15. Draw the structures of the following :                (2)         
(i) XeF2 
(ii) BrF3 
 
16. Write the equations involved in the following reactions:            (2) 
(i) Reimer - Tiemann reaction 
(ii)  Williamson synthesis 
 
17. Write the mechanism of the following reaction:             (2) 
 
HBr
3 2 3 2 2
CH CH OH CH CH Br+H O ? ? ? 
  
  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
18. Write the name of monomers used for getting the following polymers:         (2) 
(i) Bakelite 
(ii)  Neoprene 
 
19. (a)  Calculate ?rG
O
  for the reaction 
Mg (s) + Cu
2+
 (aq)   Mg 
2+
 (aq) + Cu (s) 
    
Given: E
0
 cell= + 2.71 V,   1 F = 96500 C mol
-1
 
 
(b)  Name the type of cell which was used in Apollo space programme 
 for providing electrical power.              (3) 
 
20. The   following   data    were   obtained during the   first   order   thermal 
decomposition of SO2Cl2 at a constant volume: 
        
2 2(g) 2 (g) 2(g)
SO Cl SO +Cl ? 
 
Experiment Time/s
-1
 Total pressure/atm 
1 0 0.4 
2 100 0.7 
 
Calculate the rate constant.               (3) 
               (Given: log 4 = 0.6021, log 2 = 0.3010 
 
21. What are emulsions? What are their different types? Give one example  
of each type.                        (3)  
22. Give reasons for the following:              (3) 
(i)  (CH3)3 P = O exists but (CH3)3 N = O does not. 
(ii)  Oxygen has less electron gain enthalpy with negative sign than sulphur. 
(iii)  H3PO2 is a stronger reducing agent than HaPO3. 
 
23. (i) Write the IUPAC name of the complex [Cr(NH3)4 Cl2]Cl. 
(ii) What type of isomerism is exhibited by the complex [Co (en) 3]
3+
? 
(en= ethane-1,2-diamine) 
  (iii) Why is [NiCl4]
2-
 paramagnetic but [Ni (CO)4] is diamagnetic? 
   (At. nos. : Cr = 24, Co = 27, Ni = 28)              (3) 
 
24. (a) Draw  the  structures of major  monohalo products  in  each  of the 
 following reactions: 
i) 
                   
 
 
  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
ii) 
      
 
(b) Which halogen compound in oach of the following pairs  will react faster  in 
SN2 reaction : 
(i) CH3Br or  CH3I 
(ii) (CH3)3 C- Cl or  CH3 -  Cl 
 
25. Account for the following:                (3) 
(i)  Primary amines (R-NH2) have higher boiling point than tertiary 
 amines (R3N). 
(ii) Aniline does not undergo Friedel - Crafts reaction. 
(iii)  (CH3)2NH  is more basic than  (CH3)3N in an aqueous solution. 
 
OR 
 
Give the structures of A, B and C in the following reactions: 
(i) 
22
NaNO +HCl H O Sn+HCl
6 5 2 273K
C H NO A B C ? ? ? ? ? ? ? ? ? ? ? ? 
(ii) 
+
3 22
NH H O/H Br +KOH
3
CH CN A B C
?
? ? ? ? ? ? ? ? ? ? ? 
 
26. Define the following terms as related to proteins:            (3) 
(i) Peptide linkage 
(ii) Primary structure 
(iii)  Denaturation 
 
27. On the occasion of World Health Day, Dr. Satpal organized a 'health camp' for the 
poor farmers living in a nearby village.  After check-up,   he was shocked to see that 
most of the farmers suffered from cancer due to regular exposure to pesticides and   
many   wore diabetic.  They   distributed free medicines to them.  Dr.  Satpal 
immodiately reported the   matter to the National Human Rights   Commission 
(NHRC).  On the suggestions of NHRC, the government decided to provide medical     
care,   financial assistance, setting up of super-specialty hospitals for treatment  
and prevention of the deadly disease  in the affected villages  all over India. 
(i) Write the values shown by 
(a)  Dr. Satpal 
(b)  NHRC. 
 
 (ii)  What type of analgesics are chiefly used for the relief of pains of 
terminal cancer? 
(iii)  Give an example of artificial sweetener that could have   been  
recommended to diabetic patients.             (3) 
  
  
 
CBSE  |  Chemistry 
Board Paper ? 2014  
 
     
 
28. (a)  Define the following terms :  
(i) Molarity 
(ii)  Molal elevation constant (Kb) 
 
(b)       A solution containing 15 g urea (molar mass = 60 g mol
-1
) per litre of solution 
in  water has  the  same  osmotic  pressure (Isotonic)  as a solution of glucose  
(molar  mass  = 180 g mol
-1
)  in water. Calculate the mass of glucose present 
in one litre of its solution.            (2,3) 
OR 
 
29.       (a)  What   type of deviation is shown   by a mixture of ethanol and acetone?  
Give reason. 
 
(b) A solution   of glucose (molar mass   = 180 g mol
-1)
 in water is labelled    
as   10%  (by  mass).   What   would be the molality and molarity of the 
solution? 
 (Density of solution= 1.2 g mL
-1
)              (2,3)
 (a)  Complete  the following equations : 
(i)  
??
?
2
27
Cr O +2OH 
 
(ii)  
??
?
+
4
MnO + 4H + 3e 
 
(b)  Account for the following: 
(i) Zn is not considered as a transition element. 
(ii)  Transition metals form a large number of complexes. 
(iii) The E
0
value for the Mn
3+
/Mn
2+ 
couple is much more positive  
than that for Cr
3+
/cr
2+
 couple.                      (2,3) 
 
OR 
 
(i) With reference to structural variability and chemical reactivity, write the 
differences between lanthanoids and actinoids. 
(ii) Name a member of the lanthanoid series which is well known to exhibit 
 +4 oxidation state. 
(iii) Complete the following equation:  
 
??
?
+
4
MnO +8H +5e 
(iv) Out of Mn
3+
 and Cr
3+
, which is more paramagnetic and why?  
(Atomic nos. : Mn =25, Cr = 24)              (5) 
 
30. (a)  Write the products formed when CH3CHO reacts with the following reagents:   
(i) HCN 
(ii) H2N - OH 
(iii) CH3CHO in the presence of dilute NaOH