Henderson

Henderson-Hasselbach equation A simplified version of the relationships used in calculations on buffer solutions. 

Barker J and Henderson D 1967 Perturbation theory and equation of state for a fluids II. A successful theory of liquids J. Chem. Phys. 47 4714... 

Barker J A and Henderson D 1976 What is a liquid Understanding the states of matter Rev. Mod. Phys. 48 587... 

Eyring H, Henderson D, Stover B J and Eyring E 1982 Statistical Mechanics and Dynamics (New York Wiley)... 

Muckerman J T 1971 Theoretical Chemistry—Advances and Perspectives vol 6A, ed H Eyring and D Henderson (New York Academic) p 1... 

Quack M and Troe J 1981 Theoretical Chemistry Advances andRerspectives vol 6B, ed E Henderson (New York Academic) p 199... 

Tree J 1975 Unimolecular reactions experiment and theory Physicai Chemistry. An Advanced Treatise vol VIB, ed H Eyring, D Henderson and W Jest (New York Academic) pp 835-929... 

Gerisoher H 1970 Physioal Chemistry vo 9, ed H Eyring, D Henderson and W dost (New York Aoademio) Morrison S R 1977 The Chemioal Physios of Surfaces (New York Plenum)... 

Hoover W G, Ross M, Johnson K W, Henderson D, Barker J A and Brown B C 1970 Soft sphere equation of state J. Chem. Phys. 52 4931-41... 

Henderson R 1995 The potential and limitations of neutrons, electrons and x-rays for atomic resolution microscopy of unstained biological molecules Q. Rev. Biophys. 28 171-93... 

Henderson P T, Jones D, Hampikian G, Kan Y Z and Schuster G B 1999 Long-distance charge transport in dupiex DNA the phonon-assisted poiaron-iike hopping mechanism Proc. Natl Acad. Sc/., USA 96 8353-8... 

Henderson, D. Fundamentals of Inhomogeneous Fluids. Marcel Dekker, New York (1992). 

Hai dka W A, R Henderson and D Oesterhelt 1995. 3-DimensionaI Structure of Halorhodopsin Angstrom Resolution. Journal of Molecular Biology 2A7 726-738. 

Henderson R, J M Baldwin, T A Ceska, F Zemlin, E Beckmann and K H Downing 1990. Model fo Structure of Bacteriorhodopsin Based on High-resolution Electron Cryo-microscopy. Joun Molecular Biology 213 899-929. 

F. E. Harris, Theoretical Chemistry Advances and Perspectives D. Henderson (Ed.) 1, 147, Academic Press, New York (1975). 

The decision to undertake this project was prompted by Barbara Goldman at John Wiley Sons, who was willing to believe in a first-time author. Her suggestions greatly improved the quality of the finished text. Darla Henderson and Jill Roter were also very helpful in bringing the project to completion and making the existence of bureaucracy transparent. 

Potentiometric determinations of the pK of thiazole and essentially its alkyl derivatives are summarized in Table T50. The most reliable values are given by Phan-Tan-Luu et al. (321), who realized a critical study of the classical Henderson method for the determination of pK. ... 

The measurement of pK for bases as weak as thiazoles can be undertaken in two ways by potentiometric titration and by absorption spectrophotometry. In the cases of thiazoles, the second method has been used (140, 148-150). A certain number of anomalies in the results obtained by potentiometry in aqueous medium using Henderson s classical equation directly have led to the development of an indirect method of treatment of the experimental results, while keeping the Henderson equation (144). 

This relationship is one form of the Henderson-Hasselbalch equation It is a useful relationship m chemistry and biochemistry One rarely needs to cal culate the pH of a solution—pH is more often mea sured than calculated It is much more common that one needs to know the degree of ionization of an acid at a particular pH and the Henderson-Hasselbalch equation gives that ratio... 

An alternative form of the Henderson-Hasselbalch equation for acetic acid is... 

Hemiketal (Section 17 8) A hemiacetal derived from a ketone Henderson-Hasselbalch equation (Section 19 4) An equa tion that relates degree of dissociation of an acid at a partic ular pH to its... 

Henderson, G. Lecture Graphic Aids for Least-Squares Analysis, /. Chem. Educ. 1988, 65, 1001-1003. 

If the initial concentrations of weak acid and weak base are greater than [H3O+] and [OH ], the general equation simplifies to the Henderson-Hasselhalch equation. 

As in Example 6.13, the Henderson-Hasselbalch equation provides a simple way to calculate the pH of a buffer and to determine the change in pH upon adding a strong acid or strong base. 

Substituting the new concentrations into the Henderson-Hasselbalch equation gives a pH of... 

Multiprotic weak acids can be used to prepare buffers at as many different pH s as there are acidic protons. For example, a diprotic weak acid can be used to prepare buffers at two pH s and a triprotic weak acid can be used to prepare three different buffers. The Henderson-Hasselbalch equation applies in each case. Thus, buffers of malonic acid (pKai = 2.85 and = 5.70) can be prepared for which... 

Although this treatment of buffers was based on acid-base chemistry, the idea of a buffer is general and can be extended to equilibria involving complexation or redox reactions. For example, the Nernst equation for a solution containing Fe + and Fe + is similar in form to the Henderson-Hasselbalch equation. 

Suppose you need to prepare a buffer with a pH of 9.36. Using the Henderson-Hasselbalch equation, you calculate the amounts of acetic acid and sodium acetate needed and prepare the buffer. When you measure the pH, however, you find that it is 9.25. If you have been careful in your calculations and measurements, what can account for the difference between the obtained and expected pHs In this section, we will examine an important limitation to our use of equilibrium constants and learn how this limitation can be corrected. 

Any solution containing comparable amounts of a weak acid, HA, and its conjugate weak base, A-, is a buffer. As we learned in Chapter 6, we can calculate the pH of a buffer using the Henderson-Hasselbalch equation. 

Pioneer Chlor- Alkali Co., Inc. Henderson, Nev. 104.3 1942 OxyTech MDC29 diaphragm 76 1... 

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