Contribution to the thermodynamics of bromophenol blue in the two-phase water-nitrobenzene extraction system

1990 ◽  
Vol 55 (11) ◽  
pp. 2606-2609 ◽  
Author(s):  
Emanuel Makrlík
Keyword(s):  
Equilibrium Distribution ◽  
Dissociation Constants ◽  
Extraction System ◽  
Bromophenol Blue ◽  
Phase Extraction ◽  
Distribution Constant ◽  
Two Phase ◽  
Nitrobenzene Phase ◽  
Phase Water ◽  
General Relations

General relations among thermodynamic parameters characterizing dissociation equilibria with species H2A, HA- and A2- (H2A is a symbol for an electroneutral undissociated acid) in a two-phase extraction system have been derived. From the extraction measurements, the equilibrium distribution constant of electroneutral bromophenol blue between the nitrobenzene phase and the aqueous one has been determined: log KD(H2A) = 3.60 ± 0.01. By using this value and further known constants and applying the mentioned relations the following values of dissociation constants of bromophenol blue in nitrobenzene saturated with water have been calculated for a temperature of 25 °C: pKaorg(H2A) = -log Kaorg(H2A) = 10.1 and pKaorg(HA-) = -log Kaorg(HA-) = 14.5.

scholarly journals Contribution to the termodynamics of 1-(2-thiazolylazo)-2-naphthol in the water-nitrobenzene extraction system

2000 ◽  
Vol 65 (8) ◽  
pp. 581-585 ◽  
Author(s):  
Emanuel Makrlik ◽  
Petr Vaňura
Keyword(s):  
Thermodynamic Parameters ◽  
Equilibrium Distribution ◽  
Dissociation Constants ◽  
Extraction System ◽  
Distribution Constant ◽  
Two Phase ◽  
Chemical Equilibria ◽  
Phase Water ◽  
General Relations

General relations among thermodynamic parameters characterizing chemical equilibria including species ?2?+, HA, H+ and A- in both phases of a two-phase water-nitrobenzene extraction system have been derived. From the extraction measurements, the equilibrium distribution constant of electroneutral 1-(2-thiazolylazo)-2-naphthol (TAN, HA) between the nitrobenzene and aqueous phases has been determined: log ATD(HA) = 3.90?0.02. By using this value and further known constants and applying the mentioned relations, the following values of dissociation constants of TAN in nitrobenzene saturated with water have been calculated for a temperature of 25?C: pKdnb(H2A+) = -log Kdnb(H2A+) = 4.9 and pKdnb(HA) = -log Kdnb(HA) = 16.5.

Ionic product of water in the nitrobenzene phase of the two-phase water-nitrobenzene extraction system

1991 ◽  
Vol 56 (4) ◽  
pp. 760-763
Author(s):  
Emanuel Makrlík
Keyword(s):  
Thermodynamic Parameters ◽  
Extraction System ◽  
Two Phase ◽  
Nitrobenzene Phase ◽  
Ionic Product ◽  
Phase Water ◽  
General Relations

General relations among thermodynamic parameters, which characterize the transfer of the ions H+ and OH- from the aqueous into nitrobenzene phase of the two-phase water-nitrobenzene extraction system and dissociation equilibria of H2O in both phases of this system, have been derived. Further, using the known parameters ionic product of water in nitrobenzene saturated with water has been evaluated for a temperature of 25°C: PnbH2O = 10-29.2 mol2 dm-6.

Stability of NH4+ and [Zn(NH3)4]2+ in nitrobenzene saturated with water

1990 ◽  
Vol 55 (11) ◽  
pp. 2610-2613 ◽  
Author(s):  
Emanuel Makrlík
Keyword(s):  
Complex Formation ◽  
Stability Constant ◽  
Thermodynamic Parameters ◽  
Extraction System ◽  
Phase Extraction ◽  
Two Phase ◽  
Complex Formation Equilibria ◽  
Formation Equilibria ◽  
General Relations

General relations among thermodynamic parameters characterizing complex-formation equilibria in both phases of a two-phase extraction system and ion transfers across the interface of this system have been derived. Using the mentioned relations and known parameters stability constant of [Zn(NH3)4]2+ and protonization constant of NH3 in nitrobenzene saturated with water have been calculated for a temperature of 25 °C.

Chemical equilibria including particles I-, I3-, I5-, and I2 in two-phase water-nitrobenzene extraction system

1990 ◽  
Vol 55 (11) ◽  
pp. 2602-2605 ◽  
Author(s):  
Emanuel Makrlík
Keyword(s):  
Thermodynamic Parameters ◽  
Aqueous Phase ◽  
Equilibrium Constants ◽  
Extraction System ◽  
Two Phase ◽  
Chemical Equilibria ◽  
Phase Water ◽  
General Relations ◽  
Homogeneous Reactions

General relations among thermodynamic parameters characterizing chemical equilibria with species I-, I3-, I5-, and I2 in the two-phase water-nitrobenzene extraction system have been derived. Furthermore, these relations have been used for calculating equilibrium constants K1aq(I3-) and K2aq(I5-) corresponding to homogeneous reactions I-(aq) + I2(aq) ⇄ I3-(aq) and I3-(aq) + I2(aq) ⇄ I5-(aq) proceeding in the aqueous phase of the system under study. Finally, stability of polyiodides I3- and I5- in both phases has been discussed.

Sign in / Sign up

Export Citation Format

Share Document