Acids, Bases, and the Nature of the Hydrogen Ion

  • R. P. Bell


The exact verbal definition of qualitative concepts is more often the province of philosophy than of physical science. However, the various definitions suggested for acids and bases have been closely linked with the development of physical chemistry and have often served to stimulate experimental work and to further our understanding of chemical processes, and we shall therefore devote some time to this subject. The definitions used in the remainder of this book will be those proposed by Brönstedl in 1923, namely, An acid is a species having a tendency to lose a proton, and a base is a species having a tendency to add on a proton. This can be represented schematically by A ⇌ B + H+, where A and B are termed a conjugate (or corresponding) acid-base pair.2 Before examining the consequences of this definition and its relation to more recent concepts we shall consider briefly the previous history of the terms ‘acid’ and ‘base’.


Lewis Acid Proton Affinity Bronsted Acid Hydrogen Halide Ethyl Diazoacetate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    J. N. Brönsted, Rec. Tray. Chim., 42, 718 (1923).CrossRefGoogle Scholar
  2. 2.
    It is frequently stated that the acid-base definition given here was put forward almost simultaneously by Brönsted and by T. M. Lowry [Chem. and Ind.,42, 43 (1923)]. However, although Lowry’s paper undoubtedly contains many of the ideas underlying this definition, especially for bases, it does not contain an explicit definition, and it is nowhere made clear that Lowry at that time regarded NH4 as an acid or CH3CO; as a base. In fact, in a later paper [J. Chem. Soc.,2562 (1927)], Lowry himself writes, More novelty is to be found in the perfectly logical conclusion of Brönsted that the anion of an acid is also a base or proton acceptor, in view of the fact that it can combine with a proton to form a molecule of the undissociated acid’: hence it does not seem justifiable to regard Lowry as one of the originators of the definition. I am indebted to the late Professor E. A. Guggenheim for calling my attention to this point. It is also noteworthy that G. N. Lewis (Valency and the Structure of Atoms and Molecules,(Reinhold, New York, 1923, p. 141) gave the same acid-base definition, and wrote, `… we may regard the ammonium ion as an acid’. However, he did not follow up the consequences of this view, and preferred the alternative definition of acids with which his name is usually associated.Google Scholar
  3. 3.
    P. Walden, Salts, Acids, and Bases: Electrolytes: Stereochemistry, Cornell, New York, 1929.Google Scholar
  4. 4.
    J. L. Gay-Lussac, Gab., Ann. Phys., 48, 341 (1814).CrossRefGoogle Scholar
  5. 5.
    E.g., A. Werner, Z. Anorg. Chem., 3, 267 (1893); 15, 1 (1897); Ber., 40, 4133 (1907).Google Scholar
  6. 6.
    G. N. Lewis, Valency and the Structure of Atoms and Molecules, Reinhold, New York, 1923.Google Scholar
  7. 7.
    See particularly D. P. N. Satchell and R. S. Satchell, Chem. Soc. Quart. Rev., 25, 171 (1971).CrossRefGoogle Scholar
  8. For summaries see: Symposium on Hard and Soft Acids and Bases, Chem. and Eng. News.,43, 90 (1965); R. G. Pearson, Science.,151, 172 (1966); Chem. in Britain,103 (1967): Survey Progr. Chem.,5, 1 (1970): M. J. Frazer, New Scientist,662 (1967).Google Scholar
  9. 9.
    J. O. Edwards, G. C. Morrison, V. F. Ross, and J. W. Schultz, J. Am. Chem. Soc., 77, 266 (1955).CrossRefGoogle Scholar
  10. 10.
    T. P. Onak, H. Landesman, R. E. Williams, and I. Shapiro, J. Phys. Chem., 63. 1533 (1959): W. D. Phillips, H. C. Miller. and E. L. Muetterties, J. Am. Chem. Soc., 81, 4496 (1959); R. J. Thompson and J. C. Davis, Jr., Inorg. Chem., 4, 1464 (1965).Google Scholar
  11. 11.
    R. P. Bell, The Proton in Chemistry, Methuen, London, 1959, pp. 13, 93.Google Scholar
  12. 12.
    For details of the evidence and further references, see R. P. Bell, J. O. Edwards, and R. B. Jones in The Chemistry of Boron and its Compounds (ed. E. L. Muetterties ), Wiley, New York, 1966. pp. 209–221.Google Scholar
  13. 13.
    A. Hantzsch, Ber., 32, 575 (1899).Google Scholar
  14. 14.
    A. Hantzsch, Z. Elektrochem., 29, 244 (1923); 30, 202 (1924); Ber., 58, 953 (1925).Google Scholar
  15. 15.
    K. J. Pedersen, Kgl. Dansk Vid. Selsk. Math-fys. Medd., 12 No. 1 (1932); J. Phys. Chem., 38, 581 (1934).Google Scholar
  16. 16.
    Hantzsch, and most later workers, made measurements in the neighbourhood of 0°C.Google Scholar
  17. 17.
    M. Eigen and J. Schoen, Z. Elektrochem., 59, 483 (1955); M. Eigen and L. De Maeyer, Z. Elektrochem., 59, 986 (1955).Google Scholar
  18. 18.
    A. Hantzsch and M. Kalb, Ber., 32, 3116 (1899): J. G. Aston, J. Am. Chem. Soc., 52, 5254 (1930): 53, 1448 (1931).Google Scholar
  19. 19.
    A. Werner, Neuere Anchauungen auf dem Gebiete der anorganischen Chemie, 2nd edn., Veweg, Braunschweig, 1909, p. 218.Google Scholar
  20. 20.
    B. E. Conway, in Modern Aspects of Electrochemistry (ed. J. O’M. Bockris and B. E. Conway), No. 3, MacDonald, London, 1964, p. 43.Google Scholar
  21. 21.
    P. A. Giguère, Rev. Chim. Minérale, 3, 627 (1966).Google Scholar
  22. 22.
    A. Volmer, Annalen, 440, 200 (1924).Google Scholar
  23. 23.
    R. E. Richards and J. A. S. Smith, Trans. Faraday Soc.,47, 1261 (1951). See also Y. Kakiuchi, H. Shono, H. Matsu, and K. Kigoshi, J. Chem. Phys.,19, 1069 (1951); J. Phys. Soc. Japan,7, 102 (1952), for HClO4•H2O.Google Scholar
  24. 24.
    E. R. Andrew and N. D. Finch, Proc. Phys. Soc., B, 70, 980 (1957).CrossRefGoogle Scholar
  25. 25.
    D. E. O’Reilly, E. M. Peterson, and J. M. Williams, J. Chem. Phys., 54, 96 (1971).CrossRefGoogle Scholar
  26. V. Luzzati, Acta Cryst.,4, 239 (1951); 6, 157 (1953); Y. K. Yoon and G. B. Carpenter, Acta Cryst.,12, 17 (1959); F. S. Lee and G. B. Carpenter, J. Phys. Chem.,63, 279 (1959); C. E. Nordman, Acta Cryst.,15, 18 (1962). A report [P. BourreMaladière, Compt. Rend.,246, 1063 (1958)] that H2SO4•H20 contains sulphuric acid molecules has been refuted by I. Taessler and I. Olovsson, [Acta Cryst.,B24, 299 (1968)], who found good evidence for H3O+ • HSO4.Google Scholar
  27. 27.
    D. E. Bethell and N. Sheppard, J. Chem. Phys., 21, 1421 (1953).CrossRefGoogle Scholar
  28. 28.
    C. C. Ferriso and D. F. Hornig, J. Chem. Phys., 23, 1464 (1955).CrossRefGoogle Scholar
  29. 29.
    D. J. Millen and E. G. Vaal, J. Chem. Soc., 2913 (1956).Google Scholar
  30. 30.
    J. T. Mullhaupt and D. F. Hornig, J. Chem. Phys., 24, 169 (1956); R. C. Taylor and G. L. Vidale, J. Am. Chem. Soc., 78, 5999 (1956).Google Scholar
  31. 31.
    H. G. Grimm, Z. Elektrochem., 31, 474 (1925).Google Scholar
  32. 32.
    J. Sherman, Chem. Rev., 11, 164 (1932).CrossRefGoogle Scholar
  33. 33.
    V. Kondratiev and N. D. Sokolov, Zh. Fiz. Khim., 29, 1265 (1955); F. W. Lampe and J. H. Futtrell, Trans. Faraday Soc., 59, 1957 (1963).Google Scholar
  34. 34.
    S. I. Vetchinkin, E. I. Pshenichnov, and N. D. Sokolov, Zh. Fiz. Khim., 33, 1269 (1959).Google Scholar
  35. 35.
    Ref. 13, p. 59.Google Scholar
  36. 36.
    P F. Knewstubb and A. W. Tickner, J. Chem. Phys., 36, 674 (1962); 38, 464 (1963).Google Scholar
  37. 37.
    H. D. Beckey, Z. Naturforsch., 14a, 712 (1959); 15a, 822 (1960).Google Scholar
  38. 38.
    D. Van der Raalte and A. G. Harrison, Canad. J. Chem., 41, 3118 (1963); see also M. A. Haney and J. L. Franklin, J. Chem. Phys., 50, 2028 (1969).Google Scholar
  39. 39.
    V. L. Tal’rose and E. L. Frankevich, Dokl. Akad. Nauk S.S.S.R., 111, 376 (1956); J. Am. Chem. Soc., 80, 2344 (1958).Google Scholar
  40. 40.
    J. L. Beauchamp and S. E. Butterill, J. Chem. Phys., 48, 1783 (1968); see also J. Long and B. Munson, J. Chem. Phys., 53, 1356 (1970).Google Scholar
  41. 41.
    For a summary up to 1963, see J. L. J. Rosenfeld, J. Chem. Phys.,40, 384 (1964); Acta Chem. Scand.,18, 1719 (1964). It is interesting to note that theory predicts a positive t H of 40–60 kcal mol-1 for the reaction H3O++H+ H402+; the last species has never been detected experimentally.Google Scholar
  42. 42.
    D. M. Bishop, J. Chem. Phys., 43, 4453 (1965).CrossRefGoogle Scholar
  43. 43.
    R. Gaspar, I. Tamassy-Lentei, and V. Kruglyak, J. Chem. Phys., 36, 740 (1962); J. W. Moskowitz and M. C. Harrison, J. Chem. Phys., 43, 3550 (1965).Google Scholar
  44. 44.
    A. C. Hopkinson, N. K. Holbrook, K. Yates, and I. G. Cszimadia, J. Chem. Phys., 49, 3596 (1968).CrossRefGoogle Scholar
  45. 45.
    H. Goldschmidt and O. Udby, Z. Phys. Chem., 60, 728 (1907); H. Goldschmidt, Z. Elektrochem., 15, 4 (1909).Google Scholar
  46. 46.
    It is reasonable to assume by analogy that the ‘hydrogen ion’ in an alcohol ROH has the formula ROH, hence that the equilibrium can be written ROH; +H2O ROH+H3O+; however, this cannot be deduced from experiments in which the concentration of the alcohol is effectively constant.Google Scholar
  47. 47.
    G. Bredig, Z. Elektrochem., 18, 535 (1912); W. S. Miller, Z. Phys. Chem., 85, 129 (1913).Google Scholar
  48. 48.
    G. Nonhebel and H. B. Hartley, Phil. M1dag., 50, 734 (1925); L. Thomas and E. Marum, Z. Phys. Chem., 143, 213 (1929).Google Scholar
  49. 49.
    P. Gross, A. Jamöck, and F. Patat, Monatsh., 63, 124 (1933).Google Scholar
  50. 50.
    L. S. Bagster and B. D. Steele, Trans. Faraday Soc., 8, 51 (1912); L. S. Bagster and G. Cooling, J. Chem. Soc., 693 (1920).Google Scholar
  51. 51.
    M. Schneider and P. A. Giguère, Compt. Rend., B, 267, 551 (1968).Google Scholar
  52. 52.
    See, e.g., R. Suhrmann and F. Breyer, Z. Phys. Chem., 23B, 193 (1933).Google Scholar
  53. 53.
    M. Falk and P. A. Giguère, Canad. J. Chem., 35, 1195 (1957); 36, 1680 (1958).Google Scholar
  54. 54.
    C. G. Swain and R. F. W. Bader, Tetrahedron, 10, 182 (1960); C. G. Swain, R. F. W. Bader, and E. R. Thornton, Tetrahedron, 10, 200 (1960); W. R. Busing and D. F. Hornig, J. Phys. Chem., 65, 284 (1961).Google Scholar
  55. 55.
    M. Eigen and L. de Maeyer, Z. Elektrochem., 60, 1037 (1956); The Structure of Electrolytic Solutions (ed. W. J. Hamer ), Wiley, New York, 1959, p. 64.Google Scholar
  56. 56.
    M. Eigen, Angew. Chem., 75, 489 (1963).CrossRefGoogle Scholar
  57. 57.
    B. E. Conway, J. O’M. Bockris, and H. Linton, J. Chem. Phys., 24, 834 (1956).CrossRefGoogle Scholar
  58. 58.
    L. Hall, Phys. Rer., 73, 775 (1948).CrossRefGoogle Scholar
  59. 59.
    T. Ackermann, Z. Phys. Chem (Frankfurt), 27, 253 (1961).CrossRefGoogle Scholar
  60. 60.
    R. More O’Ferrall, G. W. Koeppl, and A. J. Kresge, J. Am. Chem. Soc., 93, 1 (1971).CrossRefGoogle Scholar
  61. 61.
    E. G. Weidemann and G. Zundel, Z. Phys., 198, 288 (1967); G. Zundel, Angew. Chem. Internat. Edn., 8, 499 (1969).Google Scholar
  62. 62.
    K. Fajans and G. Joos, Z. Phys. Chem., 23, 1, 31 (1924).Google Scholar
  63. 63.
    E. Wicke, M. Eigen, and T. Ackermann, Z. Phys. Chem. (Frankfurt), 1, 340 (1954).CrossRefGoogle Scholar
  64. 64.
    E. Glueckauf, Trans. Faraday Soc., 51, 1235 (1955).CrossRefGoogle Scholar
  65. 65.
    R. P. Bell and K. N. Bascombe, Disc. Faraday Soc., 24, 158 (1957). A similar treatment for concentrated alkaline solution leads to a hydration number of 3 for the hydroxide ion; cf. G. Yagil and M. Anbar, J. Am. Chem. Soc., 85, 2376 (1963); R. Stewart and J. P. O’Donnell, Canad. J. Chem., 42, 1681 (1964).Google Scholar
  66. 66.
    A. H. Laurence, D. E. Campbell, S. E. Wiberley, and H. M. Clark, J. Phys. Chem., 60, 901 (1956); D. G. Tuck and R. M. Diamond, J. Phys. Chem., 65, 193 (1961).Google Scholar
  67. 67.
    E. Glueckauf and G. P. Kitt, Proc. Roy. Soc., A, 228, (1955).Google Scholar
  68. 68.
    J. Rudolph and H. Zimmermann, Z. Phys. Chem. (Frankfurt), 43, 311 (1964).Google Scholar
  69. 69.
    J. O. Lundgren and I. Olovsson, J. Chem. Phys., 49, 1068 (1968).CrossRefGoogle Scholar
  70. 70.
    A. C. Pavia and P. A. Giguère, J. Chem. Phys., 52, 3551 (1970).CrossRefGoogle Scholar
  71. 71.
    I. Olovsson, J. Chem. Phys., 49, 1063 (1968).CrossRefGoogle Scholar
  72. 72.
    R. D. Gillard and G. Wilkinson, J. Chem. Soc., 1640 (1964).Google Scholar
  73. 73.
    A. S. Gilbert and N. Sheppard, J. Chem. Soc., D, 337 (1971).Google Scholar
  74. 74.
    J. M. Williams and S. W. Petersen, J. Am. Chem. Soc., 91, 776 (1969); D. E. O’Reilly, E. M. Peterson, C. E. Scheie, and J. M. Williams, J. Chem. Phys., 55, 5629 (1971).Google Scholar
  75. 75.
    P. Kebarle, Advances in Chemistry, 72 (Am. Chem. Soc., 1968 ), p. 24.Google Scholar
  76. 76.
    M. de Paz, J. J. Leventhal, and L. Friedman, J. Chem. Phys., 49, 5543 (1968).CrossRefGoogle Scholar
  77. 77.
    M. de Paz, A. G. Giardini, and L. Friedman, J. Chem. Phys., 52, 687 (1970).CrossRefGoogle Scholar
  78. 78.
    E. C. Baughan, J. Chem. Soc., 1403 (1940).Google Scholar
  79. 79.
    H. F. Halliwell and S. C. Nyburg, Trans. Faraday Soc., 59, 1126 (1963). These authors give a useful summary of earlier estimates of this quantity. Conway prefers a slightly higher value, but gives an upper limit of 267 kcal mol-1. See also N. A. Izmailov, Zh. Fiz. Khim., 34, 2414 (1960).Google Scholar
  80. 80.
    J. T. Edward and I. C. Wang, Canad. J. Chem., 40, 399 (1962): G. Yagil and M. Anbar, J. Am. Chem. Soc., 85, 2376 (1963).Google Scholar
  81. 81.
    J. L. Moruzzi and A. V. Phelps, J. Chem. Phys., 45, 4617 (1966).CrossRefGoogle Scholar

Copyright information

© R. P. Bell 1973

Authors and Affiliations

  • R. P. Bell
    • 1
  1. 1.University of StirlingScotland

Personalised recommendations