Question Bank No: 1

1. Aluminium oxide may be electrolysed at 10000C to give Al metal (at mass = 27 amu, 1F=96.500 C).To prepare 5.12 kg of Al would require

 a)5.49×101C
 b)5.49×104C
 c)1.83×107C
 d)5.49×107C

2. The standard e.m.f of a galvanic cell involving cell reaction with n = 2 is found to be 0.295 V at 250C. The equilibrium constant of reaction would be

 a)2×1011
 b)4.0×1012
 c)1.0×102
 d)1×1010

3. The standard emf of Daniel cell is 1.10 volts.The maximum electrical work obtained from the cell is

 a)212.3kJ
 b)175.4kJ
 c)106.15kJ
 d)53.07kJ

4. The electrode potential of hydrogen electrode at pH 10 is

 a)0.51V
 b)0.00V
 c)-0.59V
 d)0.059V

5. In a H2O2 fuel cell, 6.72 L of hydrogen at NTP reacts in 15 minutes, the average current produced in ampere is

 a)64.3 amp
 b)643.3 amp
 c)6.43 amp
 d)0.643 amp

6. Certain quality of current liberated 0.507g of hydrogen in 2 hr.The number of grams of copper that can be liberated by same under similar conditions will be approximately

 a)12.7 g
 b)16.0 g
 c)31.8 g
 d)63.5 g

7. When KMnO4acts as an oxidising agent and ultimately forms MnO42,MnO2,Mn2O3 and Mn2+then the number of electrons transferred in each case respectively is

 a)4,3,1,5
 b)1,5,3,7
 c)1,3,4,5
 d)3,5,7,1

8. The electrolysis of acqueous solution of CuBr2 using platinum electrode would lead to the evolving of

 a)O2 gas at anode
 b)Br2gas t anode and O2gas T cathode
 c)Coppers (s) at cathode
 d)H2gas at cathode

9. The depolarizer used in dry cell batteries is

 a)NH4Cl
 b)manganese dioxide
 c)Potassium hydroxide
 d)Sodium triphosphide

10. Zn rod is placed in 100 mL of 1 M CuSO4 solution so that molarity of Cu2+change to 0.7 M.The molarity of SO42 ions at this stage will be

 a)0.8 M
 b)1M
 c)0.7 M
 d)1.8 M

11. In which of the following compound Cl exhibits more than one oxidation states?

 a)CaOCl2
 b)CaCl2
 c)Cl2O7
 d)ICI3

12. In which of the following compound, valency of carbon is 4 but its oxidation number is zero

 a)methane
 b)carbon dioxide
 c)carbon monoxide
 d)Formaldehyde

13. Magnesium reacts with acids producing hydrogen and corresponding magnesium salts. In such reaction magnesium undergoes

 a)oxidation
 b)reduction
 c)neither oxidation nor reduction
 d)simple dissolution

14. Which of the following is the most powerful oxidising agent?

 a)F2
 b)Cl2
 c)Br2
 d)l2

15. Molar conductivity of a solution is 1.26 ×102 Ω1Cm2 mol1 . Its molarity is 0.01. Its specific conductivity will be

 a)1.26 ×1025
 b)1.26 ×103
 c)1.26 ×104
 d)0.0063

16. At infinite dilution, the aqueous solution of BaCl2 , molar conductivity of Ba2+ ans Cl ions are = 127 . 32 Scm2/mol and 76.34 Scm2/mol respectively.What is m for BaCl2 at same dilution?

 a)280 Scm2mol1
 b)330.98 Scm2mol1
 c)90.98 Scm2mol1
 d)203.6 Scm2mol1

17. The specific conductance of a 0.1 N KCl solution at 230C is 0.012 ohm1cm1. The resistance of cell containing the solution at the same temperature was found to be 55 ohm. The cell constant will be

 a)0.142cm1
 b)0. 66cm1
 c)0.918cm1
 d)1.12cm1

18. At STP 1.12 litre of H2 is obtained on flowing a current for 965 seconds in a solution. The value of current is

 a)10
 b)1.0
 c)1.5
 d)2.0

19. Reaction takes place at anode is

 a)ionisation
 b)reduction
 c)oxidation
 d)hydrolysis

20. Electrode potentials(E0red) of 4 elements A,B,C,D are - 1.36, -0.32, 0, -1.26 V respectively. The decreasing reactivity order of these elements is

 a)A,D,B and C
 b)C,B,D and A
 c)B,D,C and A
 d)C, A,D and B

21. The standard reduction potential of Li+/Li,
Ba 2 + / Ba , Na + / Na and Mg2+/Mg, are -3.05,-2.73,-2.71 and -2.37 volts respectively which one of the following is strongest oxidising agent?

 a)Na+
 b)Li+
 c)Ba2+
 d)Mg2+

22. In a galvanic cell

 a)Chemical energy is converted into electricity
 b)Chemical energy is converted into heat
 c)Electrical energy is converted into heat
 d)Electrical energy is converted into chemical energy

23. Out of Cu, Ag, Fe and Zn , the metal which can displace all others from their salt solution is

 a)Ag
 b)Cu
 c)Zn
 d)Fe

24. A current of 9.65 ampere flowing for 10 minutes deposits 3.0g of the metal which is monovalent. The atomic mass of the metal is

 a)10
 b)50
 c)25
 d)100

25. What weight of copper will be deposited by passing 2 faradays of electricity through a cupric salt (At. wt. of Cu = 63.5)

 a)2.0 g
 b)3.175 g
 c)63.5 g
 d)127.0 g

26. If a strip of copper metal is placed in a solution of ferrous sulphate

 a)Copper will precipitate out
 b)Iron will precipitate out
 c)Copper and iron both will be dissolved
 d)No reaction will take place

27. What is the standard cell potential for the cell?
Zn ; Zn2+/Zn2+(1M)Cu2+(1M);Cu
( E 0 for Zn2+/Zn=0.76;E0 for Cu2+/Cu=+0.34

 a)- 0.76 + (-0.34) = -0.42V
 b)- 0.34 + 0.76 = + 0.42 V
 c)0.34 - (-0.76) = +1.10 V
 d)- 0.76 -(+0.34) = -1.10 V

28. If a salt bridge is removed between the two half cells, the voltage

 a)Drops to Zero
 b)Does not charge
 c)Increases gradually
 d)Increases rapidly

29. When the same quantity of electricity is passed through the solution of different electrolytes in series, the amounts of product obtained are proportional to their

 a)Atomic weights
 b)Chemical equivalents
 c)Gram molecular volume
 d)Gram atomic ions

30. In electrolysis of very dilute NaOH using platinum electrodes

 a)H2 is evolved at anode
 b)NH3 is produced at anode
 c)Cl2 is obtained at cathode
 d)O2 is produced at anode

31. The strongest reducing agent is

 a)k
 b)Mg
 c)Al
 d)Br

32. The charge on cobalt in [Co(CN)6]3 is

 a)-6
 b)-3
 c)+3
 d)+6

33. Oxidation number of oxygen atom in O2 molecule is

 a)0
 b)-2
 c)+2
 d)12

34. A reducing agent is a substance which can

 a)accept electrons
 b)donate electrons
 c)accept protons
 d)donate protons

35. Consider the reaction Zn + Cu2+Zn2+Cu
With reference of the above, which one of the following is the correct statement?

 a)Zn is reduced to Zn2+
 b)Zn is oxidized to Zn2+
 c)Zn2+ is oxidized to Zn
 d)Cu2+ is oxidized to Cu

36. Carbon is in the lowest oxidation state in

 a)CH4
 b)CCl2
 c)CF4
 d)CO2

37. The oxidation number of Mn in KMnO4 is

 a)+7
 b)-7
 c)+1
 d)-1

38. In which of the following compounds transition metal is in zero oxidation state?

 a)[Co(NO3)6]Cl2
 b)[Fe(H2O)8]SO4
 c)[Ni(CO)4]
 d)[Fe(H2O)3](OH)2

39. Oxygen has an oxidation state of +2 in

 a)H2O2
 b)H2O
 c)OF2
 d)SO2

40. Which of the following is the strongest oxidizing agent?

 a)F2
 b)Cl2
 c)Br2
 d)I2

41. In which reaction there is change in O.N. of N atom

 a)2NO2N2O4
 b)2N2O+H2OHNO3+HNO2
 c)NH4OH NH4++OH
 d)N2O5+H2O2HNO3

42. Oxidation number of S in S2O32 is

 a)-2
 b)+2
 c)+6
 d)0

43. In the reaction, H2O2+Na2CO3Na2O2+CO2+H2O.. The substance under going oxidation is

 a)H2O2
 b)none
 c)Na2CO3
 d)Na2O2

44. The process in which oxidation number increase is known as

 a)oxidation
 b)reduction
 c)auto-oxidation
 d)none of the above

45. In a reaction between zinc and iodine, zinc iodide is formed, what is being oxidized?

 a)Zinc ions
 b)Iodide ions
 c)Zinc atom
 d)iodine

46. Which of the following reactions involves oxidation and reduction?

 a)NaBr + HCl NaCl+ HBr
 b)HBr + AgNO3AgBr+HNO3
 c)H2+Br22HBr
 d)Na2O+H2SO4Na2SO4+H20

47. When iron is added to CuSO4 solution, copper is precipitated. It is due to

 a)oxidation of Cu+2
 b)Reduction of Cu+2
 c)Hydrolysis of CuSO4
 d)Ionization of CuSO4