Thermodynamic Data and E pH Diagrams

1101

Thermodynamic Data and E-pH Diagrams

The tables and graphics in this appendix describe the thermodynam-ic behavior of the following metals when exposed to pure water at 25and 60°C:

■ Chromium1,2

■ Copper3,4

■ Iron5–8

■ Manganese9,10

■ Nickel11–13

■ Zinc9,14

Tables F.1 to F.6 contain the basic thermodynamic values for eachspecies, solid or ionic, considered for the construction of the E-pH dia-grams. The graphics were obtained with a publicly available softwaresystem that has been used throughout the book to calculate differentequilibrium systems.15 The basic calculations were detailed in Sec. D.2,Chemical Thermodynamics. The relations between the free energy ofthe species considered and the associated equations are evaluated withthe data presented in Tables F.1 to F.6 and the following equations. Thefree energy (G0) of a substance for which heat capacity data are avail-able can be calculated as a function of temperature using Eq. (F.1).

G(T2)0 � G(T1)

0 � S(T1)0 (T2 � T1) � T2

� T2

T1

dT � � T2

T1

C0p dT (F.1)

C0p

�

T

APPENDIX

F

T1

T2

T1

T2

0765162_AppF_Roberge 9/1/99 8:29 Page 1101

1102 Appendix F

TABLE F.1 Species Considered for the Cr-H2O System and TheirThermodynamic Data

G0(298 K), S0

(298 K), Species J�mol�1 J�mol�1 A B � 103 C � 10�5

O2 0 205 29.96 4.184 �1.674H2 0 131 27.28 3.263 0.502H2O �237,000 69.9 75.27 0 0Cr 0 23.77 17.41 15.15 1.26CrO �350,661 44.77 46.48 8.12 �3.68Cr2O3 �1,058,134 81.17 119.37 9.2 �15.65CrO2 �539,740 48.12 67.49 12.55 �12.55CrO3 �502,080 73.22 75.86 16.78 �8.37Cr(OH)3 �900,815 80.33 0 0 0CrOOH �672,955 25.1 0 0 0

S0(298 K,

J�mol�1 a b

H� 0 0 �20.9 0.065 �0.005Cr2� �176,146 �104.6 �146.44 0.13� 0.00166Cr3� �215,476 �307.52 �370.28 0.13 �0.00166Cr(OH)2� �430,950 �68.62 �110.46 0.13 �0.00166Cr(OH)2

� �632,663 �144.77 �165.69 0.13 �0.00166CrO4

2� �727,849 50.21 92.05 �0.37 0.0055HCrO4

� �764,835 184.1 205.02 �0.37 0.0055CrO2

� �535,929 96.23 117.15 �0.37 0.0055CrO3

3� �603,416 �238.49 �175.73 �0.37 0.0055

TABLE F.2 Pure Species Considered for the Cu-H2O System andTheir Thermodynamic Data

G0(298 K), S0

(298 K), Species J�mol�1 J�mol�1 A B � 103 C� 10�5

O2 0 205 29.96 4.184 �1.674H2 0 131 27.28 3.263 0.502H2O �237,000 69.9 75.27 0 0Cu 0 33.2 22.635 6.276 0Cu2O �147,904 92.4 62.62 0 0CuO �127,905 42.6 42.32 0 0Cu(OH)2 �358,987 87 87.91 0 0

S0(298 K),

J�mol�1 a b

H� 0 0 �20.9 0.065 �0.005Cu� 50,626 �12.6 �33.52 0.13 �0.00166Cu2� 65,689 �207.2 �249.04 0.13 �0.00166Cu(OH)� �129,704 41.89 20.97 0.13 �0.00166Cu2(OH)2

2� �280,328 �98.22 �140.06 0.13 �0.00166Cu3� 303,340 �401.8 �464.56 0.13 �0.00166HCuO2

� �258,571 96.38 117.3 �0.37 0.0055CuO2

2� �183,678 �98.22 �56.38 �0.37 0.0055CuO2

� �112,550 96.38 117.3 �0.37 0.0055


Thermodynamic Data and E-pH Diagrams 1103

TABLE F.3 Pure Species Considered for the Fe-H2O System and TheirThermodynamic Data

G0(298 K), S0


O2 0 205 29.96 4.184 �1.674H2 0 131 27.28 3.263 0.502H2O �237,000 69.9 75.27 0 0Fe 0 27.1 12.72 31.71 �2.51Fe3O4 �1,020,000 146 91.55 201.67 0Fe2O3 �742,000 87.3 98.28 77.82 �14.85Fe(OH)2 �493,000 92.4 96.3 0 0Fe(OH)3 �714,000 96.1 105 0 0

S0(298 K),

J�mol�1 a b

H� 0 0 �20.9 0.065 �0.005Fe(OH)2(sln) �449,000 38 38 0.13 �0.00166Fe(OH)3(sln) �661,000 75.2 75.2 0.13 �0.00166FeOH� �274,000 �29.3 �50.2 0.13 �0.00166Fe(OH)2

� �459,000 �29.3 �50.2 0.13 �0.00166Fe2� �92,200 �107 �149 0.13 �0.00166FeOH2� �242,000 �105 �147 0.13 �0.00166Fe3� �17,800 �279 �342 0.13 �0.00166Fe(OH)3

� �621,000 41.8 62.7 �0.37 0.0055Fe(OH)4

� �843,000 25.1 46 �0.37 0.0055FeO4

2� �467,000 37.6 79.5 �0.37 0.0055

TABLE F.4 Pure Species Considered for the Mn-H2O System and TheirThermodynamic Data

G0(298 K), S0


O2 0 205 29.96 4.184 �1.674H2 0 131 27.28 3.263 0.502H2O �237,000 69.9 75.27 0 0Mn 0 32.0076 23.8488 14.14192 �1.54808MnO �362,920 59.70568 46.48424 8.11696 �3.68192Mn3O4 �1,283,233 155.6448 144.9338 45.27088 �9.2048Mn2O3 �881,150 110.4576 103.4703 35.06192 �13.5143MnO2 �465,177 53.05312 69.4544 10.20896 �16.2339

S0(298 K),

J�mol�1 a b

H� 0 0 �20.9 0.065 �0.005Mn2� �228,028 �115.478 �157.34 0.13 �0.00166Mn(OH)� �405,011 �37.656 �58.576 0.13 �0.00166Mn3� �82,006.4 �378.652 �441.41 0.13 �0.00166HMnO2

� �507,101 62.76 83.68 �0.37 0.0055MnO4

� �447,270 212.1288 233.05 �0.37 0.0055MnO4

2� �500,825 100.416 142.256 �0.37 0.0055


1104 Appendix F

TABLE F.5 Pure Species Considered for the Ni-H2O System and TheirThermodynamic Data

G0(298 K), S0


O2 0 205 29.96 4.184 �1.674H2 0 131 27.28 3.263 0.502H2O �237,000 69.9 75.27 0 0Ni 0 30.12 16.99 294.55 0Ni(OH)2 �453,130 79.5 0 0 0NiO �215,940 38.58 �20.88 157.23 16.28Ni3O4 �711,910 146.44 129.03 71.46 �23.93Ni2O3 �469,740 94.14 98.28 77.82 �14.85NiO2 �215,140 52.3 69.45 10.21 �16.23

S0(298 K),

J�mol�1 a b

H� 0 0 �20.9 0.07 �0.01Ni2� �46,442 �201.3 �243.14 0.13 0HNiO2

� �349,218 62.76 41.84 �0.37 0.01

TABLE F.6 Pure Species Considered for the Ni-H2O System and TheirThermodynamic Data

G0(298 K), S0


O2 0 205 29.96 4.184 �1.674H2 0 131 27.28 3.263 0.502H2O �237,000 69.9 75.27 0 0Zn 0 41.63 25.4 0 0Zn(OH)2 �559,358 81.6 72.4 0 0

S0(298 K),

J�mol�1 a b

H� 0 0 �20.9 0.065 �0.005Zn2� �147,280 �207.2 �249.04 0.13 �0.00166Zn(OH)� �329,438 41.89 20.97 0.13 �0.00166HZnO2

� �464,227 96.38 117.3 �0.37 0.0055ZnO2

2� �389,424 �98.22 �56.38 �0.37 0.0055


For pure substances, i.e., solids, liquids, and gases, the heat capacityCp

0 is expressed as an empirical function of the absolute temperature[Eq. (F.2)].

Cp0 � A � BT � CT�2 (F.2)

For ionic substances, one has to use another method, such as that proposed by Criss and Cobble in 1964,16 to obtain the heat capacity, pro-vided that the temperature does not rise above 200°C. The expression ofthe ionic capacity [Eq. (F.3)] makes use of absolute entropy values andthe parameters a and b contained in Tables F.1 to F.6.

Cp0 � (4.186a � bS0

(298 K)) (T2 � 298.16) / ln � � (F.3)

By combining Eq. (F.2) or (F.3) with Eq. (F.1), one can obtain the freeenergy [Eq. (F.4)] at a given temperature by using the fundamentaldata contained in Tables F.1 to F.6.

Gt0 � G0

(298 K) � (Cp0 � S0

(298 K)) (T2 � 298.16)

� T2 ln � � Cp0 (F.4)

Table F.7 provides an index for the thermodynamic data of the speciesconsidered, the equations possible, and associated E-pH diagrams attwo temperatures, 25 and 60°C.

References

1. Silverman, D.C., Absence of Cr(IV) in the EMF-PH Diagram for Chromium,Corrosion, 39:488–491 (1983).

2. Lee, J. B., Elevated Temperature Potential-pH Diagrams for the Cr-H2O, Mo-H2O,and Pt-H2O Systems, Corrosion, 37:467 (1981).

3. Bianchi, G., and Longhi, P., Copper in Sea-Water, Potential-pH Diagrams, CorrosionScience, 13:853–864 (1973).

4. Duby, P., The Thermodynamic Properties of Aqueous Inorganic Copper Systems,INCRA Monograph IV, New York, The International Copper Research Association,1977.

5. Le, H. H., and Ghali, E., Interpretation des diagrammes E-pH du système Fe-H2Oen relation avec la fragilisation caustique des aciers, Journal of AppliedElectrochemistry, 23:72–77 (1993).

6. Silverman, D. C., Presence of Solid Fe(OH)2 in EMF-pH Diagram for Iron,Corrosion, 38:453–455 (1982).

7. Townsend, H. E., Potential-pH Diagrams at Elevated Temperature for the SystemFe-H2O, Corrosion Science, 10:343–358 (1970).

8. Biernat, R. J., and Robins, R. G., High-Temperature Potential/pH Diagrams for theIron-Water and Iron-Water-Sulphur Systems, Electrochimica Acta, 17:1261–1283(1972).

9. Pourbaix, M., Atlas of Electrochemical Equilibria in Aqueous Solutions, Houston,Tex., NACE International, 1974.

T2�298.16

T2�298.16



10. Macdonald, D. D., The Thermodynamics and Theoretical Corrosion Behavior ofManganese in Aqueous Systems at Elevated Temperatures, Corrosion Science,16:482 (1976).

11. Macdonald, D. D., The Thermodynamics of Metal-Water Systems at ElevatedTemperatures, Part 4, The Nickel-Water System, AECL-4139, Pinawa, Canada,Whiteshell Nuclear Research Establishment, 1972.

12. Chen, C. M., and Theus, G. J., Chemistry of Corrosion-Producing Salts in LightWater Reactors, NP-2298, Palo Alto, Calif., Electric Power Research Institute, 1982.

13. Cowan, R. L., and Staehle, R. W., The Thermodynamics and Electrode KineticBehavior of Nickel in Acid Solution in the Temperature Range 25° to 300°C, Journalof the Electrochemical Society, 118:557–568 (1971).

14. Pan, P., and Tremaine, P. R., Thermodynamics of Aqueous Zinc: Standard PartialMolar Heat Capacities and Volumes of Zn2� (aq) from 10 to 55°C, Geochimica etCosmochimica Acta, 58:4867–4874 (1994).

15. Roberge, P. R., KTS-Thermo (2.01), Kingston, Canada, Kingston Technical Software,1998.

16. Criss, C. M., and Cobble, J. W., The Thermodynamic Properties of HighTemperature Aqueous Solutions, Journal of the American Chemical Society,86:5385–5393 (1964).

1106 Appendix F

TABLE F.7 Index to Thermodynamic Data, Equilibrium, andAssociated E-pH Diagrams for Important Engineering Metals

Element Equations Temperature, °C Figure

Chromium (Data Table F.1)Hydrated state Table F.8 25 F.1

60 F.2Dry state Table F.9 25 F.3

60 F.4Copper (Data Table F.2)

Hydrated state Table F.10 25 F.560 F.6

Dry state Table F.11 25 F.760 F.8

Iron (Data Table F.3)Hydrated state Table F.12 25 F.9


60 F.12Manganese (Data Table F.4)

Table F.14 25 F.1360 F.14

Nickel (Data Table F.5)Hydrated state Table F.15 25 F.15


60 F.18Zinc (Data Table F.6)

Table F.17 25 F.1960 F.20



TABLE F.8 Possible Reaction in the Cr-H2O Systembetween the Species Most Stable in Wet Conditions

Equilibria

1. 2 e� � 1CrO � 2H� � 1Cr � 1H2O2. 1 e� � 1Cr(OH)3 � 1H� � 1CrO � 2H2O3. 3 e� � 1Cr(OH)3 � 3H� � 1Cr � 3H2O4. 1 e� � 1CrO2 � 1H2O � 1H� � 1Cr(OH)35. 1 e� � 1CrO2 � 1H� � 1Cr(OH)36. 3 e� � 1CrO3 � 3H� � 1CrO2 � 1H2O7. 2 e� � 1Cr2� � 1Cr8. 3 e� � 1CrO2

� � 4H� � 1Cr � 2H2O9. 6 e� � 1HCrO4

� � 7H� � 1Cr � 4H2O10. 6 e� � 1CrO4

2� � 8H� � 1Cr � 4H2O11. 1 e� � 1CrO2

� � 2H� � 1CrO�1H2O12. 1CrO2

� � 1H2O�1H� � 1Cr(OH)313. 1CrO3 � 1H2O � 1CrO4

2� � 2H�

14. 1CrO3 � 1H2O � 1HCrO4� � 1H�

15. 1CrO�2H� � 1Cr2� � 1H2O16. 3 e� � 1Cr3� � 1Cr17. 3 e� � 1CrO3

3� � 6H� � 1Cr � 3H2O18. 1 e� � 1CrO3

3� � 4H� � 1CrO�2H2O19. 1 e� � 1CrO2 � 4H� � 1Cr3� � 2H2O20. 2 e� � 1HCrO4

� � 3H� � 1CrO2 � 2H2O21. 2 e� � 1CrO4

2� � 4H� � 1CrO2 � 2H2O22. 1Cr(OH)3 � 3H� � 1Cr3� � 3H2O23. 1Cr(OH)3 � 1CrO3

3� � 3H�

24. 1 e� � 1Cr(OH)3 � 3H� � 1Cr2� � 3H2O25. 3 e� � 1HCrO4

� � 4H� � 1Cr(OH)3 � 1H2O26. 3 e� � 1CrO4

2� � 5H� � 1Cr(OH)3 � 1H2O27. 3 e� � 1CrO4

2� � 4H� � 1CrO2� � 2H2O

28. 3 e� � 1CrO42� � 2H� � 1CrO3

3� � 1H2O29. 1CrO2

� � 4H� � 1Cr3� � 2H2O30. 1CrO3

3� � 2H� � 1CrO2� � 1H2O

31. 1CrO42� � 1H� � 1HCrO4

�

32. 1 e� � 1Cr3� � 1Cr2�

33. 1 e� � 1CrO2� � 4H� � 1Cr2� � 2H2O

34. 3 e� � 1HCrO4� � 7H� � 1Cr3� � 4H2O

35. 3 e� � 1CrO42� � 8H� � 1Cr3� � 4H2O

36. 3 e� � 1HCrO4� � 3H� � 1CrO2

� � 2H2O37. 1Cr(OH)3 � 2H� � 1Cr(OH)2� � 2H2O38. 1Cr(OH)3 � 1H� � 1Cr(OH)2

� � 1H2O39. 1 e� � 1CrO2 � 3H� � 1Cr(OH)2� � 1H2O40. 1Cr(OH)2� � 1H� � 1Cr3� � 1H2O41. 1Cr(OH)2

� � 1H� � 1Cr(OH)2� � 1H2O42. 1CrO2

� � 2H� � 1Cr(OH)2�

43. 1 e� � 1Cr(OH)2� � 1H� � 1Cr2� � 1H2O44. 1 e� � 1Cr(OH)2

� � 2H� � 1Cr2� � 2H2O45. 3 e� � 1CrO4

2� � 7H� � 1Cr(OH)2� � 3H2O46. 3 e� � 1CrO4

2� � 7H� � 1Cr(OH)2� � 3H2O47. 3 e� � 1HCrO4

� � 5H� � 1Cr(OH)2� � 2H2O

48. 3 e� � 1CrO42� � 6H� � 1Cr(OH)2

� � 2H2O49. 1CrO2

� � 3H� � 1Cr(OH)2� � 1H2O


1108 Appendix F

TABLE F.9 Possible Reactions in the Cr-H2O Systembetween the Species Most Stable in Dry Conditions

Equilibria

1. 2 e� � 1CrO�2H� � 1Cr � 1H2O2. 2 e� � 1Cr2O3 � 2H� � 2CrO�1H2O3. 6 e� � 1Cr2O3 � 6H� � 2Cr � 3H2O4. 2 e� � 2CrO2 � 2H� � 1Cr2O3 � 1H2O5. 6 e� � 2CrO3 � 6H� � 1Cr2O3 � 3H2O6. 2 e� � 1CrO3 � 2H� � 1CrO2 � 1H2O7. 2 e� � 1Cr2� � 1Cr8. 3 e� � 1CrO2

� � 4H� � 1Cr � 2H2O9. 6 e� � 1HCrO4

� � 7H� � 1Cr � 4H2O10. 6 e� � 1CrO4

2� � 8H� � 1Cr � 4H2O11. 1 e� � 1CrO2

� � 2H� � 1CrO�1H2O12. 2CrO2

� � 2H� � 1Cr2O3 � 1H2O13. 1CrO3 � 1H2O � 1CrO4

2� � 2H�

14. 1CrO3 � 1H2O � 1HCrO4� � 1H�

15. 1CrO�2H� � 1Cr2� � 1H2O16. 3 e� � 1Cr3� � 1Cr17. 3 e� � 1CrO3

3� �r � 3H2O18. 1 e� � 1CrO3

3� � 4H� � 1CrO�2H2O19. 1 e� � 1CrO2 � 4H� � 1Cr3� � 2H2O20. 2 e� � 1HCrO4

� � 3H� � 1CrO2 � 2H2O21. 2 e� � 1CrO4

2� � 4H� � 1CrO2 � 2H2O22. 1Cr2O3 � 6H� � 2Cr3� � 3H2O23. 1Cr2O3 � 3H2O � 2CrO3

3� � 6H�

24. 2 e� � 1Cr2O3 � 6H� � 2Cr2� � 3H2O25. 6 e� � 2HCrO4

� � 8H� � 1Cr2O3 � 5H2O26. 6 e� � 2CrO4

2� � 10H� � 1Cr2O3 � 5H2O27. 3 e� � 1CrO4

2� � 4H� � 1CrO2� � 2H2O

28. 3 e� � 1CrO42� � 2H� � 1CrO3

3� � 1H2O29. 1CrO2

� � 4H� � 1Cr3� � 2H2O30. 1CrO3

3� � 2H� � 1CrO2� � 1H2O

31. 1CrO42� � 1H� � 1HCrO4

�

32. 1 e� � 1Cr3� � 1Cr2�

33. 1 e� � 1CrO2� � 4H� � 1Cr2� � 2H2O

34. 3 e� � 1HCrO4� � 7H� � 1Cr3� � 4H2O

35. 3 e� � 1CrO42� � 8H� � 1Cr3� � 4H2O

36. 3 e� � 1HCrO4� � 3H� � 1CrO2

� � 2H2O37. 1Cr2O3 � 4H� � 2Cr(OH)2� � 1H2O38. 1Cr2O3 � 1H2O�2H� � 2Cr(OH)2

�

39. 1 e� � 1CrO2 � 3H� � 1Cr(OH)2� � 1H2O40. 1Cr(OH)2� � 1H� � 1Cr3� � 1H2O41. 1Cr(OH)2

� � 1H� � 1Cr(OH)2� � 1H2O42. 1CrO2

� � 2H� � 1Cr(OH)2�

43. 1 e� � 1Cr(OH)2� � 1H� � 1Cr2� � 1H2O44. 1 e� � 1Cr(OH)2

� � 2H� � 1Cr2� � 2H2O45. 3 e� � 1CrO4

2� � 7H� � 1Cr(OH)2� � 3H2O46. 3 e� � 1CrO4

2� � 7H� � 1Cr(OH)2� � 3H2O47. 3 e� � 1HCrO4

� � 5H� � 1Cr(OH)2� � 2H2O

48. 3 e� � 1CrO42� � 6H� � 1Cr(OH)2

� � 2H2O49. 1CrO2

� � 3H� � 1Cr(OH)2� � 1H2O



TABLE F.10 Possible Reactions in the Cu-H2OSystem between the Species Most Stable in WetConditions

Equilibria

1. 3H� � 1HCuO2� � 2H2O�1Cu2�

2. 4H� � 1CuO22� � 2H2O�1Cu2�

3. 1H� � 1CuO22� � 1HCuO2

�

4. 1 e� � 1Cu2� � 1Cu�

5. 1 e� � 3H� � 1HCuO2� � 1Cu� � 2H2O

6. 1 e� � 4H� � 1CuO22� � 2H2O�1Cu�

7. 2 e� � 2H� � 1Cu2O � 1H2O�2Cu8. 2 e� � 2H� � 1Cu(OH)2 � 2H2O�1Cu9. 2 e� � 2H� � 2Cu(OH)2 � 3H2O�1Cu2O

10. 2H� � 1Cu2O � 1H2O�2Cu�

11. 2H� � 1Cu(OH)2 � 2H2O�1Cu2�

12. 2H� � 1CuO22� � 1Cu(OH)2

13. 1 e� � 1Cu� � 1Cu14. 2 e� � 1Cu2� � 1Cu15. 2 e� � 3H� � 1HCuO2

� � 2H2O�1Cu16. 2 e� � 4H� � 1CuO2

2� � 2H2O�1Cu17. 2 e� � 1H2O � 2Cu2� � 2H� � 1Cu2O18. 2 e� � 4H� � 2HCuO2

� � 3H2O�1Cu2O19. 2 e� � 6H� � 2CuO2

2� � 3H2O�1Cu2O20. 1 e� � 2H� � 1Cu(OH)2 � 2H2O�1Cu�

TABLE F.11 Possible Reactions in the Cu-H2O Systembetween the Species Most Stable in Dry conditions

Equilibria

1. 3H� � 1HCuO2� � 2H2O�1Cu2�

2. 4H� � 1CuO22� � 2H2O�1Cu2�

3. 1H� � 1CuO22� � 1HCuO2

�

4. 1 e� � 1Cu2� � 1Cu�

5. 1 e� � 3H� � 1HCuO2� � 1Cu� � 2H2O

6. 1 e� � 4H� � 1CuO22� � 2H2O�1Cu�

7. 2 e� � 2H� � 1Cu2O � 1H2O�2Cu8. 2 e� � 2H� � 1CuO � 1H2O�1Cu9. 2 e� � 2H� � 2CuO � 1H2O�1Cu2O

10. 2H� � 1Cu2O � 1H2O�2Cu�

11. 2H� � 1CuO � 1H2O�1Cu2�

12. 1H� � 1HCuO2� � 1H2O�1CuO

13. 1 e� � 1Cu� � 1Cu14. 2 e� � 1Cu2� � 1Cu15. 2 e� � 3H� � 1HCuO2

� � 2H2O�1Cu16. 2 e� � 4H� � 1CuO2

2� � 2H2O�1Cu17. 2 e� � 1H2O�2Cu2� � 2H� � 1Cu2O18. 2 e� � 4H� � 2HCuO2

� � 3H2O�1Cu2O19. 2 e� � 6H� � 2CuO2

2� � 3H2O�1Cu2O20. 1 e� � 2H� � 1CuO � 1H2O�1Cu�


TABLE F.12 Possible Reactions in the Fe-H2O Systembetween the Species Most Stable in Wet Conditions

Equilibria

1. 2 e� � 2H� � 1H22. 4 e� � 1O2 � 4H� � 2H2O3. 2 e� � 1Fe(OH)2 � 2H� � 1Fe�2H2O4. 2 e� � 1Fe2� � 1Fe5. 2 e� � 1Fe(OH)3

� � 3H� � 1Fe�3H2O6. 1 e� � 1Fe(OH)3 � 1H� � 1Fe(OH)2 � 1H2O7. 1 e� � 1Fe(OH)3 � 3H� � 1Fe2� � 3H2O8. 1Fe(OH)3

� � 1H� � 1Fe(OH)2 � 1H2O9. 1 e� � 1Fe(OH)3 � 1Fe(OH)3

�

10. 1Fe3� � 3H2O � 1Fe(OH)3 � 3H�

11. 1Fe2� � 2H2O � 1Fe(OH)2 � 2H�

12. 1 e� � 1Fe3� � 1Fe2�

13. 1Fe2� � 1H2O � 1FeOH� � 1H�

14. 1FeOH� � 1H2O � 1Fe(OH)2(sln) � 1H�

15. 1Fe(OH)2(sln) � 1H2O � 1Fe(OH)3� � 1H�

16. 1Fe3� � 1H2O � 1FeOH2� � 1H�

17. 1FeOH2� � 1H2O � 1Fe(OH)2� � 1H�

18. 1Fe(OH)2� � 1H2O � 1Fe(OH)3(sln) � 1H�

19. 1 e� � 1FeOH2� � 1H� � 1Fe2� � 1H2O20. 1 e� � 1Fe(OH)2

� � 2H� � 1Fe2� � 2H2O21. 1 e� � 1Fe(OH)3(sln) � 1H� � 1Fe(OH)2(sln) � 1H2O22. 1 e� � 1Fe(OH)3(sln) � 2H� � 1FeOH� � 2H2O23. 1 e� � 1Fe(OH)3(sln) � 3H� � 1Fe2� � 3H2O

TABLE F.13 Possible Reactions in the Fe-H2O Systembetween the Species Most Stable in Dry Conditions

Equilibria

1. 2 e� � 2H� � 1H22. 4 e� � 1O2 � 4H� � 2H2O3. 8 e� � 1Fe3O4 � 8H� � 3Fe�4H2O4. 2 e� � 1Fe2� � 1Fe5. 2 e� � 1Fe(OH)3

� � 3H� � 1Fe�3H2O6. 2 e� � 3Fe2O3 � 2H� � 2Fe3O4 � 1H2O7. 2 e� � 1Fe3O4 � 8H� � 3Fe2� � 4H2O8. 2 e� � 1Fe2O3 � 6H� � 2Fe2� � 3H2O9. 2 e� � 1Fe3O4 � 5H2O � 3Fe(OH)3

� � 1H�

10. 2Fe3� � 3H2O � 1Fe2O3 � 6H�

11. 1 e� � 1Fe3� � 1Fe2�

12. 1Fe2� � 1H2O � 1FeOH� � 1H�

13. 1FeOH� � 1H2O � 1Fe(OH)2(sln) � 1H�

14. 1Fe(OH)2(sln) � 1H2O � 1Fe(OH)3� � 1H�

15. 1Fe3� � 1H2O � 1FeOH2� � 1H�

16. 1FeOH2� � 1H2O � 1Fe(OH)2� � 1H�

17. 1Fe(OH)2� � 1H2O � 1Fe(OH)3(sln) � 1H�

18. 1FeOH2� � 1H� � 1Fe2� � 1H2O19. 1 e� � 1Fe(OH)2

� � 2H� � 1Fe2� � 2H2O20. 1 e� � 1Fe(OH)3(sln) � 1H� � 1Fe(OH)2(sln) � 1H2O21. 1 e� � 1Fe(OH)3(sln) � 2H� � 1FeOH� � 2H2O22. 1 e� � 1Fe(OH)3(sln) � 3H� � 1Fe2� � 3H2O



TABLE F.14 Possible Reactions in the Mn-H2O System

Equilibria

1. 2 e� � 2H� � 1H22. 4 e� � 1O2 � 4H� � 2H2O3. 1Mn(OH)� � 1H� � 1Mn2� � 1H2O4. 1HMnO2

� � 3H� � 1Mn2� � 2H2O5. 1HMnO2

� � 2H� � 1Mn(OH)� � 1H2O6. 1MnO�2H� � 1Mn2� � 1H2O7. 1MnO�1H� � 1Mn(OH)�

8. 1HMnO2� � 1H� � 1MnO�1H2O

9. 2 e� � 1Mn3O4 � 8H� � 3Mn2� � 4H2O10. 2 e� � 1Mn3O4 � 5H� � 3Mn(OH)� � 1H2O11. 2 e� � 1Mn3O4 � 2H2O � 3HMnO2

� � 1H�

12. 2 e� � 1Mn2O3 � 6H� � 2Mn2� � 3H2O13. 2 e� � 1MN2O3 � 4H� � 2Mn(OH)� � 1H2O14. 2 e� � 1Mn2O3 � 1H2O � 2HMnO2

�

15. 2 e� � 1MnO2 � 4H� � 1Mn2� � 2H2O16. 2 e� � 1MnO2 � 3H� � 1Mn(OH)� � 1H2O17. 2 e� � 1MnO2 � 1H� � 1HMnO2

�

18. 1 e� � 1MnO2 � 4H� � 1Mn3� � 2H2O19. 3 e� � 1MnO4

� � 4H� � 1MnO2 � 2H2O20. 2 e� � 1MnO4

2� � 4H� � 1MnO2 � 2H2O21. 2 e� � 1MnO�2H� � 1Mn�1H2O22. 2 e� � 1Mn3O4 � 2H� � 3MnO�1H2O23. 2 e� � 3Mn2O3 � 2H� � 2Mn3O4 � 1H2O24. 2 e� � 2MnO2 � 2H� � 1Mn2O3 � 1H2O25. 2 e� � 1Mn2� � 1Mn26. 2 e� � 1Mn(OH)� � 1H� � 1Mn�1H2O27. 2 e� � 1HMnO2

� � 3H� � 1Mn�2H2O28. 3 e� � 1Mn3� � 1Mn29. 7 e� � 1MnO4

� � 8H� � 1Mn�4H2O30. 6 e� � 1MnO4

2� � 8H� � 1Mn�4H2O31. 1 e� � 1Mn3� � 1Mn2�

32. 4 e� � 1MnO42� � 8H� � 1Mn2� � 4H2O

33. 4 e� � 1MnO42� � 7H� � 1Mn(OH)� � 3H2O

34. 4 e� � 1MnO42� � 5H� � 1HMnO2

� � 2H2O35. 5 e� � 1MnO4

� � 8H� � 1Mn2� � 4H2O36. 5 e� � 1MnO4

� � 7H� � 1Mn(OH)� � 3H2O37. 4 e� � 1MnO4

� � 8H� � 1Mn3� � 4H2O38. 1 e� � 1MnO4

� � 1MnO42�


1112 Appendix F

TABLE F.15 Possible Reactions in the Ni-H2OSystem between the Species Most Stable in WetConditions

Equilibria

1. 1Ni(OH)2 � 2H� � 1Ni2� � 2H2O2. 2 e� � 8H� � 1Ni3O4 � 3Ni2� � 4H2O3. 2 e� � 6H� � 1Ni2O3 � 3H2O�2Ni2�

4. 2 e� � 4H� � 1NiO2 � 2H2O�1Ni2�

5. 2 e� � 1Ni2� � 1Ni6. 2 e� � 3H� � 1HNiO2

� � 2H2O�1Ni7. 2 e� � 2H� � 1Ni(OH)2 � 2H2O�1Ni8. 2 e� � 2H� � 2H2O�1Ni3O4 � 3Ni(OH)29. 1H� � 1HNiO2

� � 1Ni(OH)210. 2 e� � 1Ni3O4 � 2H2O � 1H� � 3HNiO2

�

11. 2 e� � 2H� � 3Ni2O3 � 1H2O�2Ni3O412. 2 e� � 2H� � 2NiO2 � 1H2O�1Ni2O313. 3H� � 1HNiO2

� � 2H2O�1Ni2�

14. 2 e� � 1H2O�1Ni2O3 � 2HNiO2�

15. 2 e� � 1H� � 1NiO2 � 1HNiO2�

TABLE F.16 Possible Reactions in the Ni-H2O Systembetween the Species Most Stable in Dry Conditions

Equilibria

1. 2 e� � 8H� � 1Ni3O4 � 3Ni2� � 4H2O2. 2 e� � 6H� � 1Ni2O3 � 3H2O�2Ni2�

3. 2 e� � 4H� � 1NiO2 � 2H2O�1Ni2�

4. 2 e� � 1Ni2� � 1Ni5. 2 e� � 2H� � 1NiO � 1Ni�1H2O6. 2 e� � 3H� � 1HNiO2

� � 2H2O�1Ni7. 2 e� � 2H� � 1Ni3O4 � 1H2O�3NiO8. 2H� � 1NiO � 1H2O�1Ni2�

9. 1H� � 1HNiO2� � 1H2O�1NiO

10. 2 e� � 1Ni3O4 � 2H2O � 1H� � 3HNiO2�

11. 2 e� � 2H� � 3Ni2O3 � 1H2O�2Ni3O412. 2 e� � 2H� � 2NiO2 � 1H2O�1Ni2O313. 3H� � 1HNiO2

� � 2H2O�1Ni2�

14. 2 e� � 1H2O�1Ni2O3 � 2HNiO2�

15. 2 e� � 1H� � 1NiO2 � 1HNiO2�



TABLE F.17 Possible Reactions in the Zn-H2O System

Equilibria

1. 2 e� � 2H� � 1H22. 4 e� � 1O2 � 4H� � 2H2O3. 3H� � 1HZnO2

� � 2H2O�1Zn2�

4. 1H� � 1Zn(OH)� � 1H2O�1Zn2�

5. 2H� � 1HZnO2� � 2H2O�1Zn(OH)�

6. 4H� � 1ZnO22� � 2H2O�1Zn2�

7. 1H� � 1ZnO22� � 1HZnO2

�

8. 2 e� � 2H� � 1Zn(OH)2 � 2H2O�1Zn9. 2H� � 1Zn(OH)2 � 2H2O�1Zn2�

10. 1H� � 1HZnO2� � 1Zn(OH)2

11. 2H�1ZnO22� � 1Zn(OH)2

12. 2 e� � 1Zn2� � 1Zn13. 2 e� � 3H� � 1HZnO2

� � 2H2O�1Zn14. 2 e� � 4H� � 1ZnO2

2� � 2H2O�1Zn

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

b

a

Cr(OH)3

Cr

HCrO4-

Cr2O72-

H2CrO4

Cr3+

Cr2+

CrO42-

CrO33-

100

10-2

10-4

10-6

Figure F.1 Potential-pH equilibrium diagram for the chromium-water sys-tem at 25°C considering the hydrated oxide forms.


1114 Appendix F

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tia

l (V

vs

. S

HE

)

pH

b

a

Cr(OH)3

HCrO4-

Cr2O72-

H2CrO4

Cr3+

Cr2+

CrO42-

CrO33-

100

10-2

10-4

10-6

Cr

Figure F.2 Potential-pH equilibrium diagram for the chromium-watersystem at 60°C considering the hydrated oxide forms.

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

b

a

Cr2O3

HCrO4-

Cr2O72-

H2CrO4

Cr3+

Cr2+

CrO42-

CrO33-

100

10-2

10-4

10-6

Cr

Figure F.3 Potential-pH equilibrium diagram for the chromium-water sys-tem at 25°C considering the dry oxide forms.



-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

b

a

Cr2O3

HCrO4-

Cr2O72-

H2CrO4

Cr2+

CrO42-

100

10-2

10-4

10-6

Cr

CrO33-

Figure F.4 Potential-pH equilibrium diagram for the chromium-water sys-tem at 60°C considering the dry oxide forms.

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

b

Cu2+

100

10-2

10-4

10-6

Cu(OH)2

CuO22-

Cu2Oa

Cu

Figure F.5 Potential-pH equilibrium diagram for the copper-water systemat 25°C considering the hydrated oxide forms.


1116 Appendix F

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

b

Cu2+

Cu(OH)2

CuO22-

Cu2Oa

Cu

100

10-2

10-4

10-6

Figure F.6 Potential-pH equilibrium diagram for the copper-water systemat 60°C considering the hydrated oxide forms.

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

b

Cu2+

100

10-2

10-4

10-6

CuO

Cu2Oa

Cu

CuO22-

Figure F.7 Potential-pH equilibrium diagram for the copper-water systemat 25°C considering the dry oxide forms.



-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

b

Cu2+

CuO

CuO22-

Cu2Oa

Cu

100

10-2

10-4

10-6

Figure F.8 Potential-pH equilibrium diagram for the copper-water systemat 60°C considering the dry oxide forms.

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

b

Fe2+

Fe3+

HFeO2-

a

100

10-2

10-4

10-6

Fe(OH)2

Fe(OH)3

HFeO2-

Fe

Figure F.9 Potential-pH equilibrium diagram for the iron-water system at25°C considering the hydrated oxide forms.


1118 Appendix F

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

b

Fe2+

Fe3+

a

100

10-2

10-4

10-6

Fe(OH)2

Fe(OH)3

HFeO2-

Fe

Figure F.10 Potential-pH equilibrium diagram for the iron-water systemat 60°C considering the hydrated oxide forms.

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

b

Fe2+

Fe3+

a

100

10-2

10-4

10-6

Fe

HFeO2-

Fe3O4

Fe2O3

Figure F.11 Potential-pH equilibrium diagram for the iron-water system at25°C considering the dry oxide forms.



-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

Fe2

Fe3+

a

100

10-2

10-4

10-6

Fe

HFeO2-

Fe3O4

Fe2O3

b

Figure F.12 Potential-pH equilibrium diagram for the iron-water systemat 60°C considering the dry oxide forms.

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

Mn2+

100

10-2

10-4

10-6

MnO4-

Mn

MnO

a

HMnO2-

Mn3O4

b

MnO2

Mn2O3

Figure F.13 Potential-pH equilibrium diagram for the manganese-watersystem at 25°C.


-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

Ni2+100

10-2

10-4

10-6

Ni

Ni(OH)2

a

HNiO2-

b

NiO2

Ni2O3

Ni3O4

Figure F.15 Potential-pH equilibrium diagram for the nickel-water sys-tem at 25°C considering the hydrated oxide forms.

1120 Appendix F

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

Mn2+

100

10-2

10-4

10-6

MnO4-

Mn

MnO

a

HMnO2-

Mn3O4

b

MnO2

Mn2O3

Figure F.14 Potential-pH equilibrium diagram for the manganese-watersystem at 60°C.



-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

Ni2+100

10-2

10-4

10-6

Ni

Ni(OH)2a

HNiO2-

b

NiO2

Ni2O3

Ni3O4

Figure F.16 Potential-pH equilibrium diagram for the nickel-water sys-tem at 60°C considering the hydrated oxide forms.

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

Ni2+100

10-2

10-4

10-6

Ni

NiOa

HNiO2-

b

NiO2

Ni2O3

Ni3O4

Figure F.17 Potential-pH equilibrium diagram for the nickel-water systemat 25°C considering the dry oxide forms.


1122 Appendix F

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

Zn2+

Zn

100

10-2

10-4

10-6a

b

Zn(OH)2

ZnO2

ZnO22-

Figure F.19 Potential-pH equilibrium diagram for the zinc-water systemat 25°C.

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

Ni2+100

10-2

10-4

10-6

Ni

NiOa

HNiO2-

b

NiO2

Ni2O3

Ni3O4

Figure F.18 Potential-pH equilibrium diagram for the nickel-water systemat 60°C considering the dry oxide forms.



Figure F.20 Potential-pH equilibrium diagram for the zinc-water systemat 60°C.

-2

-2 0 2 4 6 8 10 12 14 16

-1.5

-1

-0.5

0

0.5

1

1.5

2

Po

ten

tial

(V

vs.

SH

E)

pH

Zn2+

Zn

100

10-2

10-4

10-6a

b

ZnO2

ZnO22-

Zn(OH)2


Documents

Thermodynamic Data and E pH Diagrams