Electric chem

• 1. 1.1) 2 - Oxidation/ Fe 2+ Fe 3+ + e- Reduction/ MnO 4 2- + 8H + + 2e Mn 2+ + 4H 2 O

2. MnO 4 2- + 2Fe 2+ + 8H + Mn 2+ + 2Fe 3+ + 4H 2 O - / Fe 2+ - (Oxidizing agent)MnO 4 2- / 3. 3SO 3 2- + 2MnO 4 - + H 2 O3SO 4 2- +2MnO 2 +2OH - 2 3SO 3 2- + 6OH - 3SO 4 2- + 3H 2 O + 6e - 2MnO 4 - + 4H 2 O + 6e - 2MnO 2 + 8OH - SO 3 2- MnO 4 - 4. - S 2- , MnO 4 - , Cl - , Zn,Cr 2 O 4 2- 1) 0 Zn, Ag, Hg, Cl 2 , H 2 , P 4 ,S8 2) 5. Al 3+ Oxidation no. = +3 Cl - Oxidation no. = -1 S 2- Oxidation no. = -23) +1 +2 4) 2 H 2 O 2 , Na 2 O 2Oxidation no. = -1 6. KO 2 Oxidation no. = -1/2 OF 2 Oxidation no. = +25) +1 - 1LiAlH 4 , NaBH 4 7. 6) 8. Na +1NaCl0 Cl-1 N -3 NH 3 0 3 H 3 x (+1)N +5 NO 3 - -1 3 O3 x (-2) Mn+7MnO 4 - -1 4 O4 x (-2)K+1 KMnO 4Mn +70 4 O4 x (-2) Cu+2[Cu(NH 3 ) 4 ] 2++24 NH 3 4 x 0 9. 1.2) 1. 2. 3. 10. 4. H + OH - H 2 O 5. Fe 2+ + Cr 2 O 7 2- + H + Fe 3+ + Cr 3+ + H 2 O1) Fe 2+Fe 3+ + e - Cr 2 O 7 2- + 6e -2Cr 3+ 11. 2) 6Fe 2+ 6Fe 3+ + 6e - Cr 2 O 7 2- + 14H + + 6e - 2Cr 3+ + 7H 2 O3) 6Fe 2+ + Cr 2 O 7 2- + 14H +6Fe 3+ + 2Cr 3+ + 7H 2 O 12. 1.3 13. 1. ( Electrode )- - 2. 3. 2 14. VSalt bridgeZnCuSO 4 2-Cu 2+ Zn 2+SO 4 2- junction potential 15. VSalt bridgeZnCuSO 4 2-Cu 2+ Zn 2+SO 4 2- junction potential 16. + -+ - - +-+ -+ - + - + -+ -+ - - +-+ -+ - + +-+ -+ - + -+ -- + + - + +-+ -+ - - +-+ -+ - + - + -+ -+ - - +-+ -+ - + +-+ -+ - + -+ -- + + - + +- E j E j E j Ej Junction potential, 17. / - KCl, NH 4 NO 3 (gelatin) 18. Zn/Cu 1. ZnZn 2+ + 2e ZnSO 4 2. Cu 2+ CuSO 4 Cu 2+ + 2eCu 19. 3. (SO 4 2- ) Zn (Zn 2+ ) Cu 4. 0 20. 1. 2. 3. 4. 21. 1.4 1. //2. / Zn/Zn 2+3. , Pt/Fe 3+ ,Fe 2+ / Ag/AgCl/Cl - 22. 4. Pt ,Au ,C / Pt/H 2 /H + 5. 1) 6Fe 2+ + Cr 2 O 7 2- + 14H + 6Fe 3+ + 2Cr 3+ + 7H 2 O Pt/Fe 3+ ,Fe 2+ //Cr 3+ ,Cr 2 O 7 2- ,H + /Pt2) 6Ti 3+ + Cr 2 O 7 2- + 2H + 6TiO 2+ + 2Cr 3+ + H 2 OPt/Ti 3+ ,TiO 2+ //Cr 3+ ,Cr 2 O 7 2- ,H + /Pt 23. 1.5 (Electrode potential , E) - 0 24. H 2 (1 atm) Pt H + (1 M) 25. V - 26. 25 cK+ + e-KE 0 = -2.92 VNa + + e Na E 0 = -2.71 V2H 2 O + 2e -H 2 + 2OH -E 0 = -0.83 VCr 3+ + 3e - Cr E 0 = -0.74 V2H + (10 -7 M) + 2e -H2 E 0 = -0.41 VNi 2+ + 2e - Ni E 0 = -0.25 V2H + + 2e -H2 E 0 = 0.00 VCu 2+ + 2e - Cu E 0 = +0.337 VI 2 + 2e - I- E 0 = +0.536 V1/2O 2 + 2H + (10 -7 M) + 2e -H 2OE 0 = +0.82 VHg 2+ + 2e - Hg E 0 = +0.854 V1/2O 2 + 2H + + 2e -H 2OE 0 = +1.23 VCr 2 O 7 2- + 14H + + 2e - 2Cr 3+ + H 2 O E 0 = +1.33 VCl 2 + 2e - 2Cl - E 0 = +1.36 VAu 3+ + 3e -AuE 0 = +1.50 V , E 0 27. (E 0 ) 1) E 0 2) SHE (Standard Hydrogen Electrode) - 1 M - 1 atm - 25 c3) E 0 28. Zn 2+ +2e -Zn E0 = -0.76 VZn Zn 2+ +2e - E0 = 0.76 V4) E 0 29. 0 , E 0 - E 0 - E 30. , E cell E cell = E cathode - E anode 00 0 E cell = E cathode - E anode E 0 Zn/Zn 2+ (1 M) //Cu 2+ (1 M) /CuAnode ZnZn 2+ + 2e E 0 = +0.76 V 31. CathodeCu 2+ + 2e CuE 0 = +0.34 V Zn + Cu 2+Zn 2+ + Cu E 0 cell = +1.10 V 00 0 E cell = E cathode - E anode E 0 cell = E 0 Cu - E 0 Zn= 0.34 - (-0.76) = +1.10 V 32. E cell 1.6) (Nernst Equation) aA + bB cC + dD 33. E = E 0 RT ln [C] c [D] d nF [A] a [B] b E = E 0 RT ln QnF R = 8.314 VCK -1 mole -1 F = 96,487 CT = 298.15 K ln logE = E 0 0.0592 log Qn 34. 0 = E 0 RT ln [C] c [D] d nF [A] a [B] bE 0 = RT ln [C] c [D] dnF[A] a [B] b E 0 = RT ln k nF 35. Cd/Cd 2+ (0.015 M) E 0 Cd = -0.403 V Cd 2+ + 2e - Cd E = E 0 - 0.0592 log [Cd]n[Cd 2+ ]E = -0.403 - 0.0592 log1 2 0.015E = -0.457 V 36. 25 c Zn + Cu 2+ Zn 2+ + CuE 0 cell = +1.10 VE 0 = 0.0592 log kn1.10 = 0.0592 log k2 k = 2 x 10 37 37. Zn/Zn 2+ (1.00 x 10 -4 M)//H + (1.0 x 10 -2 M), V 3+ (1.0 x 10 -1 ),VO 2+ (1.0 x 10 -3 M)/Pt E 0 Zn = -0.763 V E 0 V 3+ = 0.337 V 2VO 2+ + 4H + + 2e -2V 3+ + 2H 2 O E cat = 0.337 - 0.0592 log[V 3+ ] 2 2[VO 2+ ] 2 [H + ] 4= 0.337 - 0.0592 log(1.0 x 10 -1 ) 22(1.0 x 10 -3 ) 2 (1.0 x 10 -2 ) 4 38. = -0.018 V Zn 2+ + 2e - ZnE an = -0.763 0.0592 log1 2 1.0 x 10 -4= -0.881 VE cell = -0.018 (-0.881)= 0.863 V 39. 1.7) (Concentration cell)V Salt bridge CuCu SO 4 2- SO 4 2-Cu 2+Cu 2+0.1 M CuSO 4 1 M CuSO 4 40. Cu/CuSO 4 (0.1M) // CuSO 4 (1.0 M)/CuAnodeCuCu 2+ (0.1 M) + 2e Cathode Cu 2+ (1.0 M) + 2e CuCu 2+ (1.0 M)Cu 2+ (0.1 M) E = E 0 RT ln c 1nF c2 E = RT ln c 1 nF c2 41. E = RT ln c 1 nF c2 E = -2.303 RT log c 1 nF c2 42. 1.8) (primary galvanic cell)- (secondary galvanic cell)- 43. 1. ZnCl 2 + NH 4 Cl+ MnO 2 + 44. ( ) Zn Zn 2+ + 2e ( )2MnO 2 + 8NH 4 + + 2e2Mn 3+ + 4H 2 O + 8NH 32MnO 2 + Zn + 8NH 4 + 2Mn 3+ + Zn 2+ + 4H 2 O + 8NH 3 Zn 2+ 45. Zn 2+ + 4NH 3[Zn(NH 3 ) 4 ] Zn 2+ + 2H 2 O + 2NH 3[Zn(NH 3 ) 2 (H 2 O) 2 ]2. + - HgO + KOH 46. ( ) Zn + OH -Zn(OH) 2 + 2e ( )HgO + 2H 2 O + 2eHg + 2OH - Zn + HgO + 2H 2 O Zn(OH) 2 + Hg 47. 1. (Pb) Pb + SO 4 2-Pb 2+ + 2e (PbO 2 ) PbO 2 + 4H + + SO 4 2- + 2e PbSO 4 + 2H 2 O PbO 2 + PbO 2 + 4H + + 2SO 4 2-2PbSO 4 + 2H 2 O 48. 2. - ( )Cd + 2OH -Cd(OH) 2 + 2e ( )NiO 2 + 2H 2 O + 2e Ni(OH) 2 + 2OH - 49. Cd + NiO 2 + 2H 2 O Cd(OH) 2 + Ni(OH) 2 = 1.3 V 50. - H 2 , CH 4- O2 51. H2O2 Pt Pd K+ Ag2O OH - CoO 52. ( ) 2H 2 + 4OH -4HO 2 + 4e ( ) O 2 + 2H 2 O + 4e 4OH - 2H 2 + O 2 2H 2 O 53. 1.9 - - 2 - 54. E cell G 55. e- -+e- Salt bridgeZn Cu Zn 2+ Cu 2+ SO 4 2-SO 4 2- 56. - +- + H+SO 4 2- 57. ( )H 2O O 2 + 2H + + 2e ( ) 2H + + 2eH2 H 2O 2H 2 + O 2 58. 1.20 (Decomposition potential) reversible potential 59. (A) E decomp (V) 60. 1 96,487 1 1 1 Ag + + e Ag Cu 2+ + e Cu 61. , Q Q = It Q = I = ( A)t = (s)96,487 F = eN A 62. F = 1.60210 x 10 -19 C x 6.02252 x 10 23 mol -1= 96,487 C mol -1 3.0 H 2 SO 4 2 ( ) H 2O O 2 + H + + e ( ) H+ + e H2 63. Q = It = 3.0 x 2 x 3600 = 21,600 C = Q/F= 21,600/96,487= 0.224 equiv = 0.224 x 32/4= 1.792 g 64. 4 127 (M.W. = 63.54) 96.5 0.012 (M.W. = 24.305) 65. 1.21) - + - +2Cl - Cl 2 +2e2Na + + 2e 2Na Na +Cl - 66. 1.22) 1. M n+ + ne -M Cu 2+ + 2e - Cu 67. 2. 2H 2 O + 2e - H 2 + 2OH - (E cell ) - ( E 0 ) Cu 2+ + 2e - CuE 0 = +0.34 V2H 2 O + 2e - H 2 + 2OH - E 0 = -0.83 V - 68. 1. 2X -X 2 + 2e - 2I -I 2 + 2e - 2. H 2OO 2 + 2H + + 2e 3. Cu Cu 2+ + 2e - 69. MM n+ + ne - (E cell ) - ( E 0 ) 2I -I 2 + 2e - E 0 = +0.54 V H 2OO 2 + 2H + + 2eE 0 = +0.815 V Cu 2+ + 2e - Cu E 0 = +0.34 V - 70. 1 M - +- + Cu CuNa + Cl - 71. - Cl - , H 2 O, Cu - H + , H 2 O, Na + 1. Na + + e -NaE 0 = -2.71 V2. 2H 2 O + 2e - H 2 + 2OH - E 0 = -0.83 V3. 2H 2 O + 2e - H 2 + 2OH - E 0 = -0.41 V (pH = 7)4. 2H + + 2e -H2 E 0 = 0.005. Cu 2+ + 2e - Cu E 0 = +0.34 V6. O 2 + 2H + (10 -7 M) + 2e -H 2O E 0 = +0.82 V7. O 2 + 2H + + 2e -H 2O E 0 = +1.23 V 72. 8. Cl 2 + 2e -2Cl - E 0 = +1.36 V ()(1) (3) ()(5), (6) (8) (3) (5) (-0.41-0.34) = -0.75 V 73. ( )Cu Cu 2+ + 2e - E 0 = +0.34 V ( ) 2H 2 O + 2e -H 2 + 2OH - E 0 = -0. 41 V 2H 2 O + CuH 2 + Cu 2+ + 2OH - E cell = -0.75 V 74. - + - + Na +Cl - 75. (3) (6) (-0.41-0.82) = -1.23 V 1.5 V(-0.41-1.5) = -1.91 V (3) (8) (-0.41-1.36) = -1.77 V 76. ( ) 2Cl - Cl 2 + 2e - E 0 = -1.36 V ( ) 2H 2 O + 2e -H 2 + 2OH - E 0 = -0. 41 V 2H 2 O + 2Cl - H 2 +Cl 2 + 2OH - E cell = -1.77 V 77. 1) 1 M H 2 SO 42) 1 M Na 2 SO 43) 1 M NaOH 1.23) ) 78. NaCl Down cell Na + + e Na 2Cl -Cl 2 + 2e - NaCl 804 c CaCl 2 600 c Na Cl 2 79. Al 2 O 3 2000 1000 c Na 3 AlF 6 2Al 3+ + 6eAl 3O 2- 3/2O 2 +6e - 80. HCl MgCl 2 NaCl 81. + -A +- Cu 2+Cu 2+ Zn 2+ Cu 2+ Fe 2+Cu 2+ CuSO 4 82. ) - + A - + Cu 2+ Cu 2+ Cu 2+ Cu 2+ Cu 2+ Cu 2+ CuSO 4 83. 1.24) - O2 - SO 2 - CO 2 - H 2O 84. Fe Fe 2+ + 2e (1) O 2 + H 2 O + 2eOH - (2) Fe + O 2 + H 2 OFe(OH) 2 2Fe(OH) 2 + O 2 + H 2 O2Fe(OH) 3 85. (1) (2) (2) (1) 86. cathodic areaO 2 + H 2 O + 2e OH -Anodic areaFeFe 2+ + 2e 87. Fe 2+ - Fe(OH) 2 Fe(OH) 3- 1. - E 0 - O 2 + H 2 O + 2e OH - 88. 89. 2. 1. - - - - 90. 2. - FeCrO 4 tributylamine - (C 4 H 9 ) 3 NH +3. Cathodic protection