The Modern Student Laboratory: Determination of the Thermodynamic Dissociation Constant of a Weak Acid by Potentiometric Acid-Base Titration: A Three-Hour Laboratory Experiment

1994 ◽  
Vol 71 (5) ◽  
pp. A120 ◽  
Author(s):  
Jaako I. Partanen ◽  
Merja H. Karki
Keyword(s):  
Laboratory Experiment ◽  
Dissociation Constant ◽  
Weak Acid ◽  
Acid Base ◽  
Laboratory Determination ◽  
Acid Base Titration ◽  
Student Laboratory

Henderson Hasselbalch Relationship and Weak Acid Titration

2019 ◽  
Author(s):  
Marc Blétry
Keyword(s):  
Theoretical Framework ◽  
Weak Acid ◽  
Acid Base ◽  
Sensitive Technique ◽  
Chemistry Students ◽  
Advanced Students ◽  
Acid Titration ◽  
Acid Base Titration ◽  
Analytical Expressions

Henderson-Hasselbalch relation is generally the simplified theoretical framework used to introduce students to acid-base titration. However, it is not always valid and its limitations should be made clear to chemistry students. The appropriate parameter to evaluate its validity is K a /C 0 , in connection with Ostwald dilution law. For more advanced students, it is possible to deduce analytical expressions that always fit accurately acid-base titrations and allow an evaluation of Henderson Hasselbalch relation. Gran plot appears as a particularly sensitive technique to the breakdown of Henderson Hasselbalch relation.

Total weak acid concentration and effective dissociation constant of nonvolatile buffers in human plasma

2001 ◽  
Vol 91 (3) ◽  
pp. 1364-1371 ◽  
Author(s):  
Peter D. Constable
Keyword(s):  
Dissociation Constant ◽  
Human Plasma ◽  
Total Concentration ◽  
Weak Acid ◽  
Strong Ion Difference ◽  
Acid Base ◽  
Horse Plasma ◽  
Using Data ◽  
Species Specific

The strong ion approach provides a quantitative physicochemical method for describing the mechanism for an acid-base disturbance. The approach requires species-specific values for the total concentration of plasma nonvolatile buffers (Atot) and the effective dissociation constant for plasma nonvolatile buffers ( K a), but these values have not been determined for human plasma. Accordingly, the purpose of this study was to calculate accurate Atot and K a values using data obtained from in vitro strong ion titration and CO2tonometry. The calculated values for Atot (24.1 mmol/l) and K a (1.05 × 10−7) were significantly ( P < 0.05) different from the experimentally determined values for horse plasma and differed from the empirically assumed values for human plasma (Atot = 19.0 meq/l and K a = 3.0 × 10−7). The derivatives of pH with respect to the three independent variables [strong ion difference (SID), Pco 2, and Atot] of the strong ion approach were calculated as follows: [Formula: see text] [Formula: see text], [Formula: see text]where S is solubility of CO2 in plasma. The derivatives provide a useful method for calculating the effect of independent changes in SID+, Pco 2, and Atot on plasma pH. The calculated values for Atot and K a should facilitate application of the strong ion approach to acid-base disturbances in humans.

Determination Methods of Dialdehyde Celluloses from Bacterial Cellulose

2007 ◽  
Vol 361-363 ◽  
pp. 507-510
Author(s):  
Yu Hong Feng ◽  
Jia Cheng Li ◽  
Qiang Lin ◽  
Su Juan Pang ◽  
Meng Ying Zhang ◽  
...  
Keyword(s):  
Bacterial Cellulose ◽  
Amino Nitrogen ◽  
Aldehyde Group ◽  
Acid Base ◽  
Titration Method ◽  
Cannizzaro Reaction ◽  
Acid Base Titration ◽  
Determination Methods ◽  
Oxidation System

This paper addresses the determination of aldehyde group (% of dialdehyde units) in dialdehyde cellulose (DACs) oxidized from bacterial cellulose (BC). With 4 determination methods, the oxidation degrees of DACs were studied: Automatic potential titration method through Schiff base reaction, Acid-base titration in Cannizzaro reaction, Metaperiodate consumption determination, and Measurement of amino nitrogen content in DAC derivatives. By comparing determination results of these methods, we found out the proper way suitable for this metaperiodate oxidation system of BC to measure the dialdehyde unit content of the DACs.

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