ISSN:
1572-8927
Keywords:
Acidic dissociation
;
2-aminopyridine
;
dissociation constant
;
hydrogen ion
;
ionization
;
pH
;
salt effect
;
seawater
;
thermodynamics of dissociation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Buffer solutions composed of 2-aminopyridinium chloride and 2-aminopyridine in synthetic seawater are useful as a supplement to buffers of ‘Tris’ (pH 8.2) and ‘Bis’ (pH 8.8) in standardizing measurements of hydrogen ion concentration (pm H or pH(SWS)) in oceanography. The dissociation constant of 2-amino-pyridinium ion over the range of salinities (S) from 30 to 40 has now been determined from the emf of cells without liquid junction at eight temperatures (T) from 278.15 to 313.15 K. The results fit the equation pK=2498.31/T−15.3274+2.4050 lnT+S(0.012928−2.9417×10−5T) with a standard deviation of 0.0023. Thermodynamic constants for the dissociation process and standard reference values of pm H and pH(SWS) were derived from the data. The pm H of the buffer consisting of 2-aminopyridinium chloride and 2-aminopyridine (each 0.04 molal) in synthetic seawater of salinity 35 varies from 7.356 at 278.15 K to 6.601 at 313.15 K.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00646030
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