The possibility of determining the activity coefficients of individual ions from acid-base titration data

1998 ◽  
Vol 95 (7) ◽  
pp. 1583-1605 ◽  
Author(s):  
I. Jano ◽  
J. E. Hardcastle
Keyword(s):  
Activity Coefficients ◽  
Acid Base ◽  
Acid Base Titration ◽  
Titration Data

The effects of catenation on the acidity constants of porphyrin [2]catenanes

2003 ◽  
Vol 07 (10) ◽  
pp. 667-673
Author(s):  
Maxwell J. Gunter ◽  
Sandra M. Farquhar ◽  
Tyrone P. Jeynes
Keyword(s):  
Diethylene Glycol ◽  
Acid Base ◽  
Acidity Constants ◽  
Electronic Interactions ◽  
Acid Base Titration ◽  
Titration Data ◽  
Electrostatic Repulsions

The acidity constants ( pK a3 and pK a4) of a series of porphyrins and their corresponding [2]catenanes where the porphyrin is over-arched with a hydroquinol or naphthoquinol polyether strap and mechanically linked to a bipyridinium macrocycle cyclobis-paraquat(4,4'-biphenylene), are calculated from acid-base titration data. As the length of the strap decreases from tetraethylene through triethylene to diethylene, the pK a values decrease, and the separation between pK a3 and pK a4 increases. In the diethylene glycol strapped derivatives, only the monocation is accessible above pH = 0. The trend in values reflects the ease of protonation which becomes increasingly difficult as the coulombic repulsions between the protonated porphyrin and the tetracationic macrocycle becomes more severe, as a consequence of enforced proximity of the two charged centres. On protonation, any electronic interactions between the interlinked subunits is replaced by strong electrostatic repulsions. This is alleviated by a 90° rotation of the tetracation and a movement away from the porphyrin; such a reorientation is possible only in the longer strapped derivatives, and is prevented in the “tight” analogues.

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.

scholarly journals THE ACTIVITY COEFFICIENTS OF CERTAIN ACID-BASE INDICATORS

1929 ◽  
Vol 82 (1) ◽  
pp. 197-246 ◽  
Author(s):  
Julius Sendroy ◽  
A. Baird Hastings
Keyword(s):  
Activity Coefficients ◽  
Acid Base

Direct Synthesis of 3,5-Dinitropyrazole Catalyzed by Newly Sulfated Nanosolid Superacid TiO2/ SO

2011 ◽  
Vol 391-392 ◽  
pp. 1296-1301
Author(s):  
Li Min Xi ◽  
Xin Xin Zhang
Keyword(s):  
Direct Synthesis ◽  
Sol Gel ◽  
Acid Base ◽  
Direct Transformation ◽  
Acid Base Titration ◽  
Optimal Reaction Condition ◽  
Superacid Catalyst ◽  
Average Size ◽  
Optimal Reaction ◽  
Xrd And Tem

The newly sulfated nanosolid superacid TiO2/SO4 prepared by sol-gel method was broadly characterized by acid base titration, XRD and TEM, which identified that the superfine solid TiO2/SO4 showing good dispersibility with average size of 27 nm belongs to kind of crystalline nanoparticles. With the help of the catalyst TiO2/SO4, the optimal reaction condition for direct transformation of pyrazole and nitrosonitric acid into 3, 5-Dinitropyrazole was n (pyrazol)=0.10 mol, m (TiO2/SO4 )＝1.5g, V(n-octannol)＝90mL, and V(nitrosonitric acid)＝50mL. Moreover, the optimal yield of the catalytic reaction reached up to 59.4% when the reaction time is 7 hours. The nanosolid superacid catalyst is still of high activity after regenerating eight times by calcination at 600。C.

Acid-Base Titration Curves in Disproportionating Redox Systems

1994 ◽  
Vol 71 (8) ◽  
pp. 632 ◽  
Author(s):  
Tadeusz Michalowski ◽  
Andrzej Lesiak
Keyword(s):  
Redox Systems ◽  
Acid Base ◽  
Titration Curves ◽  
Acid Base Titration
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