Significant results (1979 - 2013 ) (Raji Heyrovska, Ph.
(See list of publications in http://www.jh-inst.cas.cz/~rheyrovs, for work before 1979)
I. Partial dissociation and hydration of Strong electrolytes at all concentrations found to be correct (Arrhenius, Van't Hoff and Ostwald were right; see publications:1979-).
II. Distances of closest approach of ions (have been evaluated using degrees of dissociation in Bjerrum's equation; see publications: 1999).
III. "Anomalous" Stokes ionic radii explained (so-called "anomaly" disappears on using "local" instead of "bulk' viscosity in the Stokes-Einstein Eqn.; see publication: 1989).
IV. "Wet-and-measure" polarography (uses small amounts of solution held by surface tension between a silver ring and the glass capillary with Hg-drop; see publication: 1992).
V. Current spike polarography for films and surfaces (tip of the mercury drop from the glass capillary contacts the solution at the end of its drop life; see publication: 1993).
VI. Rest mass based neutron numbers, N(rm) (Use of rest masses shows that for atomic masses A > 108, N(rm) = N -1 and for A > 254, N(rm) = N - 2; see publications: 1992, 1998, 2010).
VII. Interpretation of Michelson & Morley's observations (using Galilean kinematics, without invoking the contraction of distance and dilation of time hypotheses demanded by the special theory of relativity) (First author: Albert Heyrovsky; see publication: 1994).
VIII. Mass defect due to neutrinos evaluated from nuclear mass defects (based on the fact that fusion of a proton and a neutron to form a deuteron releases a neutrino, antineutrino pair and causes a definite mass defect attributable to neutrinos. A simple equation is provided; see publications: 1998, 2010).
IX. A new theory of the energy of the hydrogen atom (shows that the Bohr radius is divided into two Golden sections pertaining to the electron and proton and that the differenec in the two terms in the Rydberg equation in spectrocopy arises due to the electrostatic energy in the ground state. This further leads to the assignment of Golden ratio based ionic radii which explain quantitatively the interionic distances in all alkali halides and also to the additivity of atomic/ionic radii in bond lengths in general; see publications: 1999 - 2011).
X. The absolute potentials of the standard hydrogen electrode and hence of redox couples of elements of the Periodic Table have been obtained, (unambigously by a new linear correlation of the gaseous ionization potentials with standard aquoeus redox potentials; see publications: 2009-).
Introduction: I got acquainted with the properties of strong electrolytes when I was working for my Ph. D. degree. Ever since, I was wondering why the theory of electrolytes was so complicated. It was based on extensions to higher concentrations of the Debye-Huckel (1923) equations, which were valid only for very dilute solutions, and there was no unified interpretation of the thermodynamic properties over the whole concentration range (e.g., see: R. A. Robinson and R. H. Stokes, Electrolyte Solutions, Butterworths, London 1955, 1970).
During the years 1979 - 1984, by a systematic analysis of the existing data on the thermodynamic properties of electrolytes, it became gradually clear to me that the assumption of complete dissociation of strong electrolytes that prevailed from 1923 onwards had to be abandoned in favor of the earlier van't Hoff's factor for non-ideality and its interpretation by Arrhenius through the idea of partial dissociation. On combining the ideas of partial dissociation and hydration (as Arrhenius himself had suggested) as pointed out by Bousefield (1917), I could show unambiguously in 1984, that the thermodynamic properties of electrolytes could be quantitatively explained using simple equations (a century after Arrhenius wrote his dissertation for the Ph. D. in 1884!).
1987 I could explain the solution properties quantitatively
from zero upto a higher concentration of about 3.5m by using
the degrees of dissociation
and hydration numbers obtained from the data on vapor pressure of solutions. It
was published in a detailed form in: R. Heyrovska, Chapter
A full paper on this was accepted with encouraging remarks in: R. Heyrovska, Journal of Electrochemical Society, 143 (1996) 1789. Thus, since solution properties could now be explained quantitatively using concentrations and volumes of ions and ion pairs and of free water, the arbitrary thermodynamic correction factors, evaluated on the assumption of complete dissociation of electrolytes, like "activity and osmotic coefficients" are unnecessary.
Since 1996, I
have extended the above work to all the alkali
halides, strong acids, bases and many more strong
electrolytes. After my talk on the subject at
Harvard University, (my host) Prof. J.N. Butler, invited me
to write a short account in his book, (R. Heyrovska in: "Ionic
Equilibrium", Ed. J.N. Butler, (John Wiley and Sons, New
York, 1998), chapter 11, pp. 477- 481), which he
had almost completed. An invited full review of my work is in: R. Heyrovska, Chemicke
Listy, 92 (1998)
In 2003, it was a great honour for me to have been awarded the Invited Plenary Lecturership in the "Svante Arrhenius Symposium" commemorating the award of the Nobel Prize to him in 1903. The text of this Lecture is in my above webpage (http://www.jh-inst.cas.cz/~rheyrovs/text-sa-.htm) and has now been published along with more data in: R. Heyrovska, Electroanalysis, 18 (2006) 351-361.
Further, I have worked out a concise equation of state for solutions of electrolytes, based on hydration and partial dissociation, which incorporates the thermodynamic laws (see: R. Heyrovska, Special Issue of ENTROPY, 6 (2004) 128). This was on the analogous lines of an equation of state that I had developed earlier for gases (presented at a conference on the Second Law of Thermodynamics in San Diego, CA, in 2002) in: R. Heyrovska, AIP Conference Proceedings, 643 (2002) 157.
Outline/summary of the work: The idea of partial dissociation of strong electrolytes in aqueous solutions due to Arrhenius was highly appreciated at a time when solution chemistry was in bad need of it. The use of the conductivity ratio for the degree of dissociation could satisfactorily explain many experimental results for dilute solutions. However, since the conductivity ratio became unsatisfactory for higher concentrations, especially for highly dissociated electrolytes like NaCl, Lewis and Randall arbitrarily introduced the "activity coefficients" as empirical non-ideality correction factors for concentrations (in the absence of an exact knowledge of the concentration of the undissociated form). Since the Debye-Huckel theory, which treated non-ideality as due to interionic interactions, was able to account for the dependence of the actvity coefficient (and other properties of electrolyte solutions) on the square root of concentration for dilute solutions, strong electrolytes were "assumed" (erroneously) to be completely dissociated as shown,
NaCl -----> Na+ + Cl- ... (1)
The DH equations
were then gradually extended by the addition of more and
more parameters for explaining the solution properties over
larger ranges of concentration (and finally upto saturation,
e.g., see the Pitzer equations in: D. G. Archer, J. Phys.
Chem. Ref. Data 28 (1999) 1 and elsewhere).
As these elaborate parametrical equations, based on the idea of complete dissociation, could not provide a molecular insight into non-ideality, the author undertook a systematic re-investigation of the available thermodynamic data as such. Eventually, by evaluating the degrees of dissociation from vapor pressure or solvent activity data, it was found that strong electrolytes are indeed only partially dissociated in aqueous solutions as originally supposed by Arrhenius a century earlier:
NaCl <=====> Na+ + Cl- ... (2)
(1- a) <=====> a + a; sum = i = (1+a)
Thus, a fraction a of one mole of NaCl dissociates into a moles each of Na+ and Cl- ions, amounting to 2a moles of ions, and (1-a) mole remains as neutral NaCl. a is the degree of dissociation at the given concentration of NaCl in the solution. The total number of moles of solute per mole of NaCl (solid) dissolved in the solution is given by the van't Hoff factor, i = (1+a) (which is the non-idealilty factor i in van't Hoff's law for electrolyte solutions).
With the degrees of dissociation and hydration numbers (both surface and bulk) obtained from the experimental values of solvent activities (aA), many thermodynamic properties could be interpreted quantitatively using simple mathematical relations, valid from zero even up to saturation in many cases. The DH equations were shown to be asymptotic laws for complete dissociation at infinite dilution. Hydration and ionic association/dissociation thus proved to be the causes of non-ideality of solution properties at all concentrtaions.
"The thermodynamic dissociation constant", K for NaCl(aq) was shown to obey the Guldberg and Waage's Law, defined as,
K = (
ci)2 /cip =
constant (at all
where ci = am/Vi is the number of moles of either ion per unit volume of solution occupied by the ions and cip= (1-a)m/Vip is the number of moles of ion pairs per unit volume of the solution occupied by the ion pairs.
now we have the exact values
of the thermodynamic "ionic molality, am" of an ion at any
molality m of the electrolyte, there is "no need for the
activity and osmotic coefficients", which are
evaluated based on the idea of complete electrolytic
R. Heyrovska, Journal of Electrochemical Society, 143 (1996) 1789.
R. Heyrovska, Chemicke Listy, 92 (1998) 157.
R. Heyrovska, Electroanalysis, 18 (2006) 351.
R. Heyrovska, Nature Precedings, http://precedings.nature.com/documents/6416/version/2
R. Heyrovska,Current Topics in Electrochemistry, 16 (2011) 47; http://www.researchtrends.net/tia/abstract.asp?in=0&vn=16&tid=19&aid=3459&pub=2011&type=3 (Full review paper)
that in a strong electrolyte like NaCl in aqueous solutions,
ion pairs are unlikely since the critical distance of
approach for ion pair formation, q ~
(1-a)/c = 2.755 Q(b); Q(b) = f(a)
where Q(b), the
Bjerrum's integral is a function of "a". For
changes linearly with 1/m and even at saturation, a < q, the
References: R. Heyrovska: Journal of Molecular Liquids, 81 (1999) 83 (Letter) and Current Science, 76 (1999) 179 (full paper).
Diwo = kT/6phoRSi ... (1)
where ho is the coefficient of viscosity of the pure
solvent (water, w) in the bulk. The "anomalous" values of RSi
are usually associated with ionic hydration. It is shown
here that the "anomaly" is actually due to the
(incorrect) use of the coefficient of viscosity of the
bulk water, ho instead of hwi, that of water adjacent to the ions. The modified Stokes-Einstein
eqn. is thus:
Diwo = kT/6phwi Rwi ... (2)
where RSi = Rwi hwi /ho and Rwi is the radius of a water molecule adjacent to ion i.
Reference: R. Heyrovska, Chemical Physics Letters, 163 (1989) 207.
This new device shows that the tiny volume
of solution that sticks by surface tension betwen a silver
ring and the end of the glass capillary of the mercury electrode is quite enough for polarogarphy,
since it gives the same polarograms as those with mercury
electrodes (both DME and HME) dipping in bigger volumes of
solution as in conventional polarography.
Reference: R. Heyrovska, Journal of Electrochemical Society, 139 (1992) L50.
This is another
new technique: the mercury drop contacts the surface or film
of the solution in a silver ring electrode at the end of its
drop life and hence a current spike is obtained and
recorded. This is sensitive to oxygen and can be used as an
oxygen sensor, also for measuring the difference between
the surface and bulk potentials (c -potential), for fast electron transfer
processes and for
detecting the polarographic maxima of the 1st and
Reference: R. Heyrovska, Langmuir, 9 (1993) 1962.
These values of N(rm) are based
the exact rest masses of the electron (me =
0.00054858 u), proton (mp = 1.0072765 u) and
neutron (mn = 1.0086649 u). Note that the conventionally
used neutron numbers (N) are based on me
= 0, mp = mn = 1 u and
are approximate. Therefore,
= [A - Z (me+ mp)]/mn ~ N only for atomic
masses A < 108, for A > 108(Ag), N(r,m) = N - 1 and for A
> 254 (Es), N(r,m) = N
References: R. Heyrovska: Journal of Chemical Education, 69 (1992) 742; 216th Meeting of the American Chemical Society, Boston, Aug. 1998, short abstract no. 11; http://precedings.nature.com/documents/4547/version/1 (2010)
interpretations usually involve the "contraction
of distance" and "dilation of time" hypotheses (as per the
special theory of relativity), which have NOT been directly experimentally
verified, M&M's observations are explained
here by a vector addition of the velocity of the Earth
with that of light assuming Galilean kinematics, WITHOUT the
contraction or dilation hypotheses.
Reference: A. Heyrovsky and R. Heyrovska, Physics Essays, 7 (1994) 265.
VIII. "Mass defect due to neutrinos" evaluated from nuclear mass defects (based on the fact that fusion of a proton and a neutron to form a deuteron releases a neutrino, antineutrino pair and causes a definite mass defect attributable to neutrinos)
The idea behind this is that a neutrino, antineutrino pair is released during the synthesis of a deuteron from a neutron and a proton. Therefore, if the neutrinos have mass, the nuclear mass defect, MD = (ZmH+Nmn) - A, where A is the atomic mass of the nuclide X(Z.N) must also contain the mass defect due to neutrinos. Based on this, it is shown here that the mass defect due to neutrinos, MD(n), for any nuclide is a definite fraction of MD:
MD(n)/MD = [Z/(ZmH+Nmn)](mn-mp)2/mn
The values of the "mass defect per nucleon due to neutrinos/antineutrinos", MDPN(n) = MD(n)/(Z+N), (which are in the expected eV range!) have been tabulated for the most abundant nuclide of everyone of the 105 elements.
References: R. Heyrovska, 216th
Meeting of the American Chemical Society, Boston, Aug. 1998, short abstract
no. 9; in book form: Arjun Consultancy & Publishing
Inc., Desktop publisher, Wayne, NJ (USA), 1998, (full paper) and
IX. A new theory of the energy of the hydrogen atom (shows that the Bohr radius is divided into two Golden sections pertaining to the electron and proton. This leads to the assignment of Golden ratio based ionic radii which explain quantitatively the interionic distances in all alkali halides and further, to the additivity of atomic/ionic radii in bond lengths.
References: R. Heyrovska, Molecular Physics, 103 (2005) 877 - 882; Chapter 12 in: "Innovations in Chemical Biology", Editor: Bilge Sener, Springer.com, January 2009; http://precedings.nature.com/documents/3292/version/1 (2009)
potential of the standard hydrogen electrode (which
was so far taken arbitrarily as zero) and of redox couples of elements
of the Periodic Table have been established unambiguously from a new
simple linear correlation of aqueous standard potentials
with gaseous ionization potentials.
References: R. Heyrovska,
Electrochemical and Solid -State Letters, 12 (2009) F29-F30; Electrochem. Soc. Trans., 25, (2010) 159-163; Electroanalysis,
22 (2010) 903,
http://precedings.nature.com/documents/4354/version/1 (2010), see also refs 136 -140, 145.
of dissociation and hydration numbers of monovalent sulphates
including ammonium sulfate (1999).
See: http://www.electrochem.org/dl/ma/196/pdfs/2041.PDF and a Table of data in: http://www.jh-inst.cas.cz/~rheyorvs
significance of transfer
coefficients and E. M. F. of concentration cells (2000, 2002).
Shows that the transfer coefficient is not merely a kinetic parameter, but is basically a thermodynamic parameter which influences the kinetics.
90. Aqueous redox potentials related to ionization potentials and electron affinities of elements by simple linear equations (2000).
Linear relations have been shown for elements in many groups in the Periodic Table. See http://www.electrochem.org/dl/ma/198/pdfs/0957.PDF
92. An estimation of the ionization potentials of actinides from a simple dependence of the aqueous standard potentials on the ionization potentials of elements including lanthanides (2000/2001).
Using the linear relation shown above in Ref. 90, the ionization potentials for the actinides (which had not been obtained before due to their instability) have been estimated: R. Heyrovska, Journal of Alloys and Compounds 323 - 324 (2001) 614. See also Ref. 136, 137 & 138 (2009, 2010) for newer estimation..
The new concise equation of state (with association/dissociation of molecules) incorporates also heat capacities, the thermodynamic laws and entropy. The fundamentals of the 2nd law are discussed: R. Heyrovska, AIP Conference Proceedings, 643 (2002) 157 - 162
The new concise equation of state (with ion association and hydration), analogous to that for gases in Ref. 98, incorportaes also heat capacities, the thermodynamic laws and entropy:R. Heyrovska, ENTROPY, 6 (2004) 128 -134
-110. Hydrogen as an atomic
While working on the ionization potentials, the author arrived at the conclusion that the ground state Bohr radius is divided into two Golden sections at the point of electrical neutrality. The ionizational potential is the difference of two terms pertaining to the proton and electron. This explains why the two oppositely charged particles do not fall into each other, and shows that the two terms in the Rydberg equation for spectra arise in the ground state term itself. The energy of hydrogen can thus be considered as the electromagnetic energy of the simplest atomic condenser with the Golden mean capacity. References: R. Heyrovska, http://flux.aps.org/meetings/YR04/DAMOP04/baps/abs/S400132.html and Molecular Physics, 103 (2005) 877 - 882
110. The Golden ratio (f), ionic and atomic radii and
bond lengths (2005).
Shows that since the Bohr radius has two Golden sections, interatomic distances (between like atoms) are divided into two Golden sections, representing meaningful anionic and cationic radii. The latter account for the full (as in alkali halides) and partial ionic (like hydrogen halides) character of some chemical bonds, and show that bond lengths, in general, are sums of atomic/ionic radii. Tables of ionic and atomic radii and bond lengths are provided.
Reference: R. Heyrovska, Special Issue of Molecular Physics, 103 (2005) 877 - 882. For more publications: see full List of publications.
111, 112. Fine-structure constant, anomalous magnetic moment, relativity factor, the Golden ratio, and the Bohr radius (2005)
Shows that the ratio of the difference in g-factors (of the electron and proton) to their sum, is equal to f-3, and that they are related to the inverse fine-structure constant (137.036) and the Golden section (360/f2 = 137.51). Sommerfeld's relativity correction factor (for the advance of the perihelion for hydrogen atom), is also explained.
Reference: R. Heyrovska and S. Narayan, http://arxiv.org/ftp/physics/papers/0509/0509207.pdf (2005)
115. Dependence of ion-water
distances on covalent radii, ionic radii in water and
distances of oxygen and hydrogen of water from ion/water
The linear dependences give the aqueous ionic radii of many different elements and lengths of the hydration bonds, which are all functions of the Golden ratio. The hydrogen bond with all the halide ions is found to be have a constant length and is the sum of the f-based cationic radius and covalent radius of hydrogen (of water).
Reference: R. Heyrovska, Chem. Phys. Letts., 429 (2006) 600 - 605.; doi:10.1016/j.cplett.2006.08.073
117. Dependence of the length of the hydrogen bond on the covalent and cationic radii of hydrogen, and additivity of bonding distances.
Reference: R. Heyrovska, Chem. Phys. Letts., 432 (2006) 3498 - 351; doi:10.1016/j.cplett.2006.10.037
120, 123, 131. Unification of all radii by their linear dependence on Bohr radii
Reference: R. Heyrovska, http://arxiv.org/ftp/arxiv/papers/0708/0708.1108.pdf
; Philippine Journal of
Science, 137 (2): 133-139, December 2008. 121, 122, 124 - 128, 130, 132 - 135, 141, 142, 144, 148, 150, 151,
152, 155: (2005 - 2011): Additivity of atomic/ionic
radii in the bond lengths of many inorganic, organic, 2D
nano-materials and biochemical molecules including in DNA.
121, 122, 124 - 128, 130, 132 - 135, 141, 142, 144, 148, 150, 151, 152, 155: (2005 - 2011): Additivity of atomic/ionic radii in the bond lengths of many inorganic, organic, 2D nano-materials and biochemical molecules including in DNA.
149. Balmer and Rydberg equations for
hydrogen spectra revisited: Bohr's ad hoc quantization of angular momentum was
and Ionic Radii of Elements and Bohr Radii from Ionization
Potentials are Linked Through the Golden Ratio. http://www.ijsciences.com/pub/pdf/V2-201303-19.pdf
International Journal of Sciences (ISSN 2305-3925) Volume 2, 82-92, Issue Mar 2013, Research Article.
Bond Lengths, Bond Angles and
Bohr Radii from Ionization Potentials Related via the
Golden Ratio for H2+,
NO2 and CO2
International Journal of Sciences (ISSN 2305-3925) Volume 2, 1-4, Issue Apr- 2013, Research Article.
XII. Women in Science (see full
articles in List of Publications)
References 1 - 15 (in pink): Publications (2002 - 2011) on suggestions for improving the academic status/situation of Women in Science.