ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Second Dissociation Constant of Two Substituted Aminomethanesulfonic Acids in Water from 5 to 55°C (1997)
    Springer
    Journal of solution chemistry 26 (1997), S. 1209-1216 
    Details
    ISSN: 1572-8927
    Keywords: MES ; TES ; emf ; standard potential ; zwitterion ; buffer solution ; activity coefficients ; dissociation constants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The equilibrium constants for the dissociation steps of (4-morpholineethanesulfonic acid) (MES) and (2-{[tris(hydroxymethyl)methyl]-1-ethanesulfonic acid (TES) have been determined at 12 and 7 different temperatures, respectively, from 5 to 55°C. The emf measurements were carried out by using a cell without liquid junction of the type: Pt; H2 (g, 1 atm) | buffer(m1), Na salt of buffer(m2), NaCl(m3) | AgCl, Ag. The pK 2 values of MES and TES at 25°C are 6.269 and 7.550. The thermodynamic quantities for the dissociation process have been calculated. These zwitterionic compounds are useful for pH control as standard buffers in the physiological region of pH 5.50 to 6.50 for MES, 6.5 to 7.5 for TES, respectively. Reliable measurements of the pH at isotonic saline solution (I = 0.16m) such as blood and plasma are important for clinical diagnosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022937324983
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Thermodynamics of the Second Dissociation Constant and Standards for pH of 3-(NMorpholino) Propanesulfonic Acid (MOPS) Buffers from 5 to 55°C (1998)
    Springer
    Journal of solution chemistry 27 (1998), S. 73-87 
    Details
    ISSN: 1572-8927
    Keywords: Dissociation constant ; buffers ; NaMOPS ; temperature dependence ; emf ; Gibbs energy ; enthalpy ; entropy ; heat capacity ; zwitterion ; liquid junction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The second dissociation constant pK2 of 3-(N-morpholino)propanesulfonic acid (MOPS) has been determined at eight temperatures from 5 to 55°C by measurements of the emf of cells without liquid junction, utilizing hydrogen electrodes and silver–silver chloride electrodes. The pK2 has a value of 7.18 ± 0.001 at 25°C and 7.044 ± 0.002 at 37°C. The thermodynamic quantities ΔG°, ΔH°, ΔS°, and ΔC p o have been derived from the temperature coefficients of the pK 2. This buffer at ionic strength I = 0.16 mol-kg−1 close to that of blood serum, has been recommended as a useful secondary pH standard for measurements of physiological fluids. Five buffer solutions with the following compositions were prepared: (a) equimolal mixture of MOPS (0.05 mol-kg−1) + NaMOPS, (0.05 mol-kg−1); (b( MOPS (0.05 mol-kg−1) + NaMOPS (0.05 mol-kg−1) + NaCl (0.05 mol-kg−1); (c) MOPS (0.05 mol-kg−1) + NaMOPS (0.05 mol-kg−1); + NaCl (0.11mol-kg−1); (d) MOPS (0.08 mol-kg−1) + NaMOPS (0.08 mol-kg−1); and (e)MOPS (0.08 mol-kg−1) + NaMOPS (0.08 mol-kg−1) + NaCl (0.08 mol-kg−1).The pH values obtained by using the pH meter + glass electrode assembly are compared with those measured from a flow–junction calomel cell saturated with KCl (cell B), as well as those obtained from cell (A) without liquid junction at 25 and 37°C. The conventional values of the liquid junction potentials E j have been obtained at 25 and 37°C for the physiological phosphate reference solution as well as for the MOPS buffers (d) and (e) mentioned above.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022692629289
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...