Electrolytic Conductance

EXERCISE-I (Conceptual Questions) 1. Build Up Your Understanding ELECTROLYTIC CONDUCTANCE Strong electrolytes are those which : (1) dissolve readily in water (2) conduct electricity (3) dissociate into ions even at high concentration (4) dissociate into ions at high dilution. 2. Molten sodium chloride conducts electricity due to the presence of : (1) free electrons (2) free ions (3) free molecules (4) free atoms of Na and Cl 3. Electrolytic conduction is due to the movement of : (1) molecules (2) atoms (3) ions (4) electrons 4. Which of the following solutions of KCl has the lowest value of equivalent conductance ? (1) 1 M (2) 0.1 M (3) .01 M (4) .001 M 5. In the equation  = sp. cond. x V, If V is the volume in cc. containing 1 equivalent of the N electrolyte then V for a solution will be: 10 (1) 10 c.c. (2) 100 c.c. (3) 1000 c.c. (4) 10,000 c.c. 6. If the specific resistance of a solution of concentration C g eq L–1 is R, then its equivalent conductance is : 100R RC (1) (2) C 1000 1000 C (3) (4) 1000R RC 7. The specific conductances in ohm–1 cm–1 of four electrolytes P, Q, R and S are given in brackets: P (5.0×10–5) Q (7.0×10–8) R (1.0×10–10) S(9.2×10–3) The one that offers highest resistance to the passage of electric current is (1) P (2) s (3) R (4) Q 8. The specific conductance· of a salt of 0. 01 M concentration is 1.061×10–4 S cm–1. Molar conductance of the same solution will be : (1) 1.061×10–4 (2) 1.061 (3) 10.61 (4) 106.1 9. Which of the following solutions of NaCl will have the highest specific condutance ? (1) 0.001 N (2) 0.1 N (3) 0.01 N (4) 1.0 N 10. The value of molar conductivity of HCl is greater than that of NaCl at a particular temperature because: (1) Molecular mass of HCl is less than that of NaCl. (2) Velocity of H+ ions is more than that of Na+ ions (3) HCl is strongly acidic (4) Ionisation of HCl is larger than that of NaCl 11. Which statement is not correct :(1) Conductance of an electrolytic solution increases with dilution (2) Conductante of an electrolytic solution decreases with dilution (3) Specific conductance of an electrolytic solution decreases with dilution (4) Equivalent conductance of an electrolytic solution increases with dilution. 12. The resistance of 0.01 N solution of an electrolyte was found to be 210 ohm at 298 K using a conductivity cell of cell constant 0.66 cm–1. The equivalent conductance of solution is :(1) 314.28 mho cm2 eq–1 (2) 3.14 mho cm2 eq–1 –1 2 –1 (3) 314.28 mho cm eq (4) 3.14 mho–1 cm2 eq–1 13. Electrolytic conduction differs from metallic conduction from the fact that in the former (1) The resistance increases with increasing temperature (2) The resistance decreases with increasing temperature (3) The resistance remains constant with increasing temperature (4) The resistance is independent of the length of the conductor 14. The specific conductance of a 0.01 M solution of KCl is 0.0014 ohm–1 cm–1 at 25°C. Its equivalent conductance (cm2 ohm–1 eq–1) is :(1) 140 (2) 14 (3) 1.4 (4) 0.14 15. Which one of the following is wrong :(1) Specific conductance increases on dilution. (2) Specific conductance decreases on dilution. (3) Equivalent conductance increases on dilution. (4) Molar conductance increases on dilution. 16. KOHLRAUSCH LAW At infinite dilution, the equivalent conductances of CH3COONa, HCl and CH3COOH are 91, 426 and 391 mho cm2 eq–1 respectively at 25°C. The equation conductance of NaCl at infinite dilution will be : (1) 126 (2) 209 (3) 391 (4) 908 17. The equivalent conductivity of 0.1 N CH3COOH at 25°C is 80 and at infinite dilution it is 400. The degree of dissociation of CH3COOH is: (1) 1 (2) 0.2 (3) 0.1 (4) 0.5 18. The limiting molar conductivities N for NaCl, KBr and KCl are 126, 152 and 150 S cm2 mol–1 respectively. The  for NaBr is : (1) 278 S cm2 mol–1 (2) 176 S cm2 mol–1 (3) 128 S cm2 mol–1 (4) 302 S cm2 mol–1 For HCl solution at 25°C, equivalent conductance at infinite dilution, is 425 ohm–1 cm2 eq–1. The specific conductance of a solution of HCl is 3.825 ohm–1 cm–1. If the degree of dissociation is 90%. The normality of the solution is :(1) 0.90 N (2) 1.0 N (3) 10 N (4) 1.2 N 19. 20. The molar conductivities  0NaOAc and  0HCl at infinite dilution in water at 25°C are 91.0 and 426.2 S cm2 mol–1 respectively. To calculate  0HOAc the additional value required is : (1)  0NaCl (2) 0H2 O (3)  0KCl (4)  0NaOH 21. The molar conductance at infinite dilution of AgNO3, AgCl and NaCl are 116:5, 121.6 and 110.3 S cm2 mol–1 respectively. The molar conductance of NaNO3 is : (1) 111.4 S cm2 mol–1 (2) 105.2 S cm2 mol–1 2 –1 (3) 130.6 S cm mol (4) 150.2 S cm2 mol–1 22. The conductivity of a saturated solution of BaSO4 is 3.06×10–6 ohm–1 cm–1 and its molar conductance is 1.53 ohm–1 cm–1 mol–1. The Ksp of BaSO4 will be (1) 4×10–12 (2) 2.5×10–9 (3) 2.5×10–13 (4) 4×10–6 23. GALVANIC CELL In the galvanic cell Cu(s) | Cu2+ (1M) || Ag+ (1 M) | Ag(s) the electrons will travel in the external circuit : (1) from Ag to Cu (2) from Cu to Ag (3) electrons do not travel in the external circuit (4) in any direction 24. The passage of electricity in the Daniell cell when Zn and Cu electrodes are connected is : (1) from Cu to Zn in the cell (2) from Cu to Zn out side the cell (3) from Zn to Cu outside the cell (4) in any direction in the cell 25. The equation representing the process by which standard reduction potential of zinc can be defined is (1) Zn2+ (s) + 2e– Zn (s) (2) Zn (g)  Zn2+ (g) + 2e– 2+ – (3) Zn (g) + 2e Zn (s) (4) Zn2+ (aq.) + 2e–  Zn (s) 26. A standard hydrogen electrode has zero electrode potential because : (1) Hydrogen is easiest to oxidize. (2) This electrode potential is assumed to be zero. (3) Hydrogen atom has only one electron. (4) Hydrogen is the lightest element. 27. Which is not true for a standard hydrogen electrode ? (1) The hydrogen ion concentration is 1M. (2) Temperature is 25°C. (3) Pressure of hydrogen is 1 bar. (4) It contains metallic conductor which does not adsorb hydrogen. E° for the half cell Zn2+ | Zn is –0.76 V. E.m.f. of the cell Zn | Zn2+ (1M) | | 2H+ (1M) | H2 (1 atm) is : (1) –0.76 V (2) +0.76 V (3) –0.38 V (4) + 0.38 V 28. 29. The chemical reaction, 2AgCl(s) + H2(g)  2HCl(aq) + 2Ag(s) taking place in a galvanic cell is represented by the notation. (1) Pt(s) | H2(g). 1bar | 1MKCl(aq) |AgCl(s) | Ag(s). (2) Pt(s) | H2(g). 1bar | 1MHCl(aq) | 1M Ag(aq) | Ag(s). (3) Pt(s) | H2 (g).1bar | 1M HCl(aq) | AgCl(s) | Ag(s). (4) Pt(s) | H2 (g).1bar | 1MHCl (aq) | Ag(s) | AgCl(s). 30. Cu(s) | Cu+2 (1 M) | | Zn+2(1 M) | Zn(s) A cell represented above should have emf. (1) Positive (2) Negative (3) Zero 31. Given electrode potentials : Fe3+ + e–  Fe2+; E° = 0.771 V I2 + 2e– 2I– ; E° = 0.536 V E° cell for the cell reaction 2Fe3+ + 2I–  2Fe2+ + I2 is (1) (2× 0.771 – 0.536) = 1.006 V (3) 0.771 – 0.536 = 0.235 V (4) Cannot be predicted (2) (0. 771 – 0.5×0.536) = 0.503 V (4) 0.536 – 0. 771 = –0.235 V 32. Which of the following is not an anodic reaction (1) Ag+  Ag – e– (2) Cu  Cu2+ + 2e– (3) Fe2+  Fe3+ + e– (4) 4OH–  2H2O + O2 + 4e– 33. Which of the following statements is correct :(1) Oxidation occur at anode in both galvanic and electrolytic cell. (2) Reduction occurs at anode in both galvanic and electrolytic cell, (3) Reduction occur at anode in electrolytic cell where as oxidation occur at cathode in galvanic cell, (4) Oxidation occur at anode in electrolytic cell where as reduction occur at anode in a galvanic cell, 34. Other things being equal, the life of a Daniell cell may be increased by :(1) Keeping low temperature (2) Using large copper electrode (3) Decreasing concentration of coppei ions (4) Using large zinc electrodes 35. 36. ELECTROCHEMICAL SERIES Zn can not displace following ions from their aqueous solution : (1) Ag+ (2) Cu2+ (3) Fe2+ (4) Na+ The standard reduction potentials at 25°C for the following half reactions are given against each : Zn2+ (aq) + 2e– ‡ˆ ˆˆ †ˆ Zn(s), –0.762V Cr3+ (aq) + 3e– ‡ˆ ˆˆ †ˆ Cr(s), –0.740 V 2H+ + 2e– ‡ˆ ˆˆ †ˆ H2(g), 0.00 V Fe3+ + 2e– ‡ˆ ˆˆ †ˆ Fe2+, 0. 77V Which is the strongest reducing agent ? (1) Zn (2) Cr (3) H2(g) (4) Fe2+ (aq) 37. Red hot carbon will remove oxygen from the oxide XO and YO but not from ZO. Y will remove oxygen from XO. Use this evidence to deduce the order of activity of the three metals X, Y and Z putting the most active first. (1) XYZ (2) ZYX (3) YXZ (4) ZXY 38. Adding powdered Pb and Fe to a solution containing 1.0 Min each of Pb+2 and Fe+2 ions, would result into the formation of :(1) More of Fe and Pb2+ ions (2) More of Fe+2 and Pb2+ ions +2 (3) More of Pb and Fe ions (4) More of Fe and Pb 39. If a spoon of copper metal is placed in a solution of ferrous sulphate : (1) Cu will precipitate out (2) Iron will precipitate (3) Cu and Fe will precipitate (4) No reaction will take place 40. Which one will liberate Br2 from KBr? (1) HI (3) Cl2 41. (2) I2 (4) SO2 Using the standard electrode potential values given below, decide which of the statements, I, II, III and IV are correct. Choose the right answer from (1), (2), (3) and (4). Fe2+ + 2e– ‡ˆ ˆˆ †ˆ Fe ; E° = –0.44 V Cu2+ + 2e– ‡ˆ ˆˆ †ˆ Cu ; Ag+ + e– ‡ˆ ˆˆ †ˆ Ag ; E° = +0.34 V E° = +0.80 V I. Copper can displace iron from FeSO4 solution. II. Iron can displace copper from CuSO4 solution. III. Silver can displace copper from CuSO4 solution. IV. Iron can displace silver from AgNO3 solution. (1) I and II (2) II and III (3) II and IV (4) I and IV 42. The standard electrode potential value of the elements A, B and Care 0.68, –2.50 and 0.50 V respectively. The order of their reducing power is: (1) A > B > C (2) A > C > B (3) C >B > A (4) B > C > A 43. The oxidation potential of Zn, Cu, Ag, H2 and Ni are 0.76 V, –0.34 V, –0.80 V, 0 V, 0.55 V respectively. Which of the following reaction will provide maximum voltage ? (1) Zn + Cu2+  Cu + Zn2+ (2) Zn + 2Ag+  2Ag + Zn2+ (3) H2 + Cu2+  2H+ + Cu 44. (4) H2 + Ni2+  2H+ + Ni The following facts are available :2X– + Y2  2Y– + X2 2W– + Y2  no reaction 2Z– + X2  2X– + Z2 Which of the following statements is correct :(1) EoW / W > EoY / Y > EoX / X > EoZ / Z (2) EoW / W < EoY / Y < EoX / X < EoZ / Z (3) E 2 2 2 2 2 2 2 2 o W / W2 o Y / Y2 o X / X 2 o Z / Z 2 o W / W2 o Y / Y2 o X / X 2 o Z / Z 2 < E > E > E (4) E >E Y > X then : (l) Y will oxidise X and not Z (2) Y will oxidise Z and not X (3) Y will oxidise both X and Z (4) Y will reduce both X and Z 47. The standard electrode potential of Zn, Ag and Cu are –0.76 V, 0.80 V and 0.34 V respectively, then : (1) Ag can oxidise Zn and Cu (2) Ag can reduce Zn2+ and Cu2+ (3) Zn can reduce Ag+ and Cu2+ (4) Cu can oxidise Zn and Ag 48. Each of the three metals x, y and z were put in turn into aqueous solution of the other two. x + salt of y (or z)  y (or z) + salt of x Which one of the following observation is incorrect? (1) y + salt of x  no action observed (2) y + salt of z  z + salt of y (3) z + salt of x  x + salt of z (4) z + salt of y  no action observed 49. A standard reduction electrode potentials of four elements are A=- 0.250 V, B = –0.140 V C = –0.126 V, D = –0.402 V The element that displaces A from its compounds aqueous solution is :(1) B (2) C (3) D (4) None of the above 50. The following four colourless salt solutions are placed in separate test tubes and a strip of Cu is placed in each solution which finally turns blue :(1) Zn(NO3)2 (2) Mg(NO3)2 (3) KNO3 (4) AgNO3 51. Which of the following displacement does not occur (1) Zn + 2H+  Zn2+ + H2    (2) Fe + 2Ag+  Fe2+ + Ag–  (3) Cu + Fe2+  Cu2+ + Fe–  (4) Zn + Pb2+  Zn2+ + Pb–  52. 53. NERNST EQUATION E°(Ni2+ /Ni) = –0.25 V E° (Au3+/Au) = 1. 50 V The emf of the voltaic cell. Ni /NF2+ (1.0 M) | | Au3+ (1.0 M) | Au is: (1) 1.25 V (2) –1.75 V (3) 1.75 V (4) 4.0 V The emf of the cell in which the following reaction Zn(S) + Ni2+ (a = 0.1) ‡ˆ ˆˆ †ˆ Zn2+ (a = 1. 0) + Ni(s) occurs, is found to be 0.5105 V at 298 K. The standard e.m.f. of the cell is:(1) –0.5105 V (2) 0.5400 V (3) 0.4810 V (4) 0.5696 V 54. The emf of the cell Tl(s) | Tl+ (0.0001 M) | | Cu2+ (0.01M) | Cu(s) is 0.83V The emf of this cell will be increased by :(1) Increasing the concentration of Cu+2 ions (2) Decreasing the concentration of Tl+ (3) Increasing the concentration of both (4) (1) & (2) both 55. The potential of hydrogen electrode ( PH 2 = 1 atm; C H = 0.1 M) at 25°C will be(1) 0.00V 56. (3) 0.118 V (4) 0.059 V Which of the following represents the potential of silver wire dipped into 0.1 M AgNO3 solution at 25°C? (1) E ored (2) ( E ored + 0.059) (3) ( E oOX – 0.059) 57. (2) –0.059 V (4) ( E ored – 0.059) The potential of a hydrogen electrode at pH = 1 is (1) 0.059 V (2) 0.00 V (3) –0.059 V (4) 0.59 V 58. Consider the reaction Cl2(g) + 2Br(aq)  2Cl– (aq) + Br2 The emf of the cell when [Cl–] = [Br2] = [Br–] = 0.01 M and Cl2 gas at 1 atm pressure will be (E° for the above reaction is = 0.29 V) (1) 0.54 V (2) 0.35 V (3) 0.24 V (4) –0.29 V 59. The standard emf for the cell reaction Zn + Cu2+  Zn2+ + Cu is 1.10 V at 25°C. The emf for the cell reaction when 0.1 M Cu2+ and 0.1 M Zn2+ solution are used at 25°C is: (1)1.10 V (2) 0.110 V (3) –1.10 V (4) –0.110 V 60. E° for F2 + 2e–  2F– is 2.8 V, E° for ½F2 + e–  F– is ? (1) 2.8 V 61. (2) 1.4 V (3) –2.8 V G° of the cell reaction AgCl(s) + ½H2(g)  Ag(s) + H+ +Cl– is –21.52 KJ G° of 2AgCl(s) +H2(g)  2Ag(s) + 2H+ + 2Cl– is : (1) –21.52 kJ (2) –10.76 kJ (3) –43.04 kJ (4) –1.4 V (4) 43.04 kJ 62. How much will the potential of Zn/Zn2+ change if the solution of Zn2+ is diluted 10 times (1) increases by 0.03 V (2) decreases by 0.03 V (3) increases by 0.059 V (4) decreases by 0.059 V 63. How much will the potential of a hydrogen electrode change when its solution initially at pH = 0 is neutralised to pH = 7 ? (1) increases by 0.059 V (2) decreases by 0. 059 V (3) increases by 0.41 V (4) decreases by 0.41 V 64. Which of the following will increase the voltage of the cell with following cell reaction Sn(s) + 2Ag+(aq)  Sn+2(aq) + 2Ag(s) (1) Increase in the size of silver rod (2) Increase in the concentration of Sn+2 ions (3) Increase in the concentration of Ag+ ions (4) Decrease in the concentration of Ag+ ions . 65. E° for the reaction Fe + Zn2+  Zn + Fe2+ is –0.35 V. The given cell reaction is: (1) feasible (2) not feasible (3) in equilibrium (4) can't say anything 66. For a reaction - A(s) + 2B+  A2+ + 2B(s) KC has been found to be 1012. The E oCell is : (1) 0.354 V (2) 0. 708 V (3) 0.0098 V 67. 68. (4) 1.36 V The standard electrode potential (E°) for OCl–/Cl– and Cl–/½Cl2 respectively are 0. 94 V and –1.36 V. The P value of OCl–/½Cl2 will be : (1) –2.20 V (2) –0.42 V (3) 0.52 V (4) 1.04 V 2+ The standard reduction potentials of Cu /Cu and Cu2/Cu+ are 0.337 V and 0.153 V respectively. The standard electrode potential of Cu+/Cu half cell is : (1) 0.184 V (2) 0.827 V (3) 0.521 V (4) 0.490 V 69. The hydrogen electrode is dipped in a solution of pH = 3 at 25°C. The potential of the cell would be : (1) 0.177 V (2) –0.177 V (3) 0.087 V (4) 0.059 V 70. What is the potential of the cell containing two hydrogen electrodes as represented below Pt; H2(g) | H+(10–8)M | | H+(0.001 M) | H2(g).Pt ; (1) –0.295 V (2) –0.0591 V (3) 0.295 V (4) 0.0591 V 71. Consider the cell Cu/Cu+2 | | Ag+ / Ag. If the concentration of Cu+2 and Ag+ ions becomes ten times then the emf of the cell will :(1) Becomes 10 times (2) Remains same (3) Increases by 0.0295 V (4) Decreases by 0.0295 V 72. The emf of the cell Ni | Ni+2 (1.0M) | | Au+3 (0.1M) | Au [E° for Ni+2/Ni = –0.25V, E° for Au+3/Au = 1.50 V] is given as :(1) 1.25 V (2) –1.75 V (3) 1.75 V (4) 1.73 V 73. ELECTROLYSIS When an electric current is passed through acidified water, 112 mL of hydrogen gas at STP collects at the cathode in 965 s. The current passed,· in ampere is: (1) 1.0 (2) 0.5 (3) 0.1 (4) 2.0 74. Two electrolytic cells one containing acidified ferrous chloride and another acidified ferric chloride are connected in series. The ratio of iron deposited at cathodes in the two cells when electricity is passed through the cells will be : (1) 3 :1 (2) 2 : 1 (3) 1 : 1 (4) 3 : 2 75. A current of 9. 65 A flowing for 10 minute deposits 3.0 g of a metal. The equivalent weight of the metal is: (1) 10 (2) 30 (3) 5.0 (4) 96.5 76. The same amount of electricity was passed through two separate electrolytic cells containing solutions of nickel. [Ni(NO3)2] and chromium nitrate [Cr(NO3)3] respectively. If 0.3 g of nickel was deposited in the first cell, the amount of chromium deposited in the other cell is :(at. wt. of Ni = 59, at. wt. of Cr = 52) (1) 0.1 g (2) 0.17 g (3) 0.3 g (4) 0.6 g 77. How many coulombs of electricity are required for the oxidation of 1 mol of H2O to O2 ? (1) 9.65×104 C (2) 4.825×105 C (3) 1.93×105 C (4) 1.93×104 C 78. When a quantity of electricity equal to that required to liberate 2.24 L of hydrogen at STP from 0.1 M aqueous H2SO4 is passed (At. mass of Cu = 63.5) then the mass of copper that will be deposited at cathode in electrolysis of 0.2 M solution of copper sulphate will be : (1) 1.59 g (2) 3.18g (3) 6.35 g (4) 12.70 g 79. 10800 C of electricity through the electrolyte deposited 2.977 g of metal with atomic mass 106.4 g mol–1. The charge on the metal cation is(1) +4 (2) +3 (3) +2 (4) + 1 80. On passing electricity through dilute H2SO4 solution the amount of substance librated at the cathode and anode are in the ratio : (1) 1 : 8 (2) 8 : 1 (3) 16 : 1 (4) 1 : 16 81. During electrolysis of fused calcium hydride, the hydrogen is produced at : (1) Cathode (2) Anode (3) Hydrogen .is not liberated at all (4) H2 produced reacts with oxygen to form water 82. A silver cup is plated with silver by passing 965 A current for one second, the mass of Ag deposited is :- (At. wt. of Ag = 107.87) (1) 9.89 g. (2) 107.87 g. (3) 1.0787 g. (4) 100.2 g. 83. Whim electricity is passed through a solution of AlCl3, 13.5 g Al is deposited. The number of Faradays must be :(1) 5.0 (2) 1.0 (3) 1.5 (4) 3.0 84. A solution of sodium sulphate in water is electrolysed using inert electrodes. The product at the cathode and anode are respectively :(1) H2, SO2 (2) O2, H2 (3) O2, Na (4) H2,O2 85. One Faraday of electricity will liberate one mole of the metal from the solution of (1) Auric chloride (2) Silver nitrate (3) Calcium chloride (4) Copper sulphate 86. When 96500 C of electricity are passed through barium chloride solution, the amount of barium deposited will be :(1) 0.5 mol (2) 1.0 mol (3) 1.5 mol (4) 2.0 mol 87. A factory produces 40 kg of calcium in two hours by elelctrolysis. How much aluminium can be produced by the same current in two hours :(At wt. of Ca = 401 At = 27) (1) 22 kg (2) 18 kg (3) 9 kg (4) 27 kg 88. What would be the ratio of moles each of Ag+, Cu+2, Fe+3 ions would be deposited by passage of same quantity of electricity through solutions of their salts :1 1 (1) 1 : 1 : 1 (2) 1: : 2 3 1 1 (3) : :1 (4) 1 : 2 : 3 3 2 89. Electrolysis of aq. CuSO4 causes: (1) An increase in pH (3) Either decrease or increase 90. 91. (2) A decrease in pH (4) None The passage of current liberates H2 at cathode and Cl2 at anode the solution is :(1) CuSO4 (aq) (2) CuCl2 (aq) (3) NaCl (aq) (4) Water COMMERCIAL CELLS When lead accumulator is charged it is: (1) an electrolytic cell (3) a Daniel cell 92. (2) a galvanic cell (4) none of the above When a lead storage battery is charged : (1) PbO2 dissolves (2) The lead electrode becomes coated with lead sulphate (3) Sulphuric acid is regenerated (4) The amount of acid decreases ANSWER KEY 1. 8. 15. 22. 29. 36. 43. 50. 57. 64. 71. 78. 85. 92. (3) (3) (1) (4) (3) (1) (2) (4) (3) (3) (3) (3) (2) (3) 2. 9. 16. 23. 30. 37. 44. 51. 58. 65. 72. 79. 86. (2) (4) (1) (2) (2) (2) (2) (3) (2) (2) (4) (1) (1) EXERCISE-I (Conceptual Questions) 3. (3) 4. (1) 5. (4) 10. (2) 11. (2) 12. (1) 17. (2) 18. (3) 19. (3) 24. (2) 25. (4) 26. (2) 31. (3) 32. (1) 33. (1) 38. (3) 39. (4) 40. (3) 45. (4) 46. (1) 47. (3) 52. (3) 53. (2) 54. (4) 59. (1) 60. (1) 61. (3) 66. (1) 67. (3) 68. (3) 73. (1) 74. (4) 75. (3) 80. (1) 81. (2) 82. (3) 87. (2) 88. (2) 89. (2) 6. 13. 20. 27. 34. 41. 48. 55. 62. 69. 76. 83. 90. (3) (2) (1) (4) (4) (3) (3) (2) (1) (2) (2) (3) (3) 7. 14. 21. 28. 35. 42. 49. 56. 63. 70. 77. 84. 91. (3) (1) (2) (2) (4) (4) (3) (4) (4) (3) (3) (4) (1)