Time, Concentration, Ionic Strength and Solvents affects on Electronic Absorption Spectra of Association between Acid-Base Indicators

Hemdan, Sokaina Saad; Jebaly, Asma Mansur Al; Ali, Fatma Khairallah

doi:10.37376/1571-000-035-008

Cited by 3 publications

(2 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…the second pKa is decreased with increasing the ionic strength in the range (0.05 -0.3 mol L -1 KCl). Further, the increase of K + ion concentrations is responsible to the lower in acidity constant as at high concentration due to increasing electrostatic shielding effect [16,34].…”

Section: The Influence Of Ionic Strength On the Electronic Absorption...mentioning

confidence: 99%

The Dependence of Acid-Base Equilbria and Acidity Constants of Congo Red in Buffer Solutions on the Ionic Strength

Hemdan

2024

JCTM

View full text Add to dashboard Cite

In this study, the spectrophotometric studies of aqueous ethanol solution of Congo red in various buffers solutions at room temperature 25oC and at different ionic strength of 0.05, 0.1, 0.3, and 0.5 KCl mol L-1 were investigated. The acidity constants of Congo red were estimated by three different methods. The two protonation stages were observed in pH range 2 - 4 and 4 - 6 as result as protonation of amino group and azo groups. The dependence of absorption spectra of Congo red on the ionic strength of solutions which exhibited blue shift with increases ionic strength in addition the shape and intensity were varied. Therefore, the acid-base equilibria shifted toward the higher pHs with the rise in ionic strength. Also, the acidity constants were affected by the ionic strength which the acidity constants decrease with increasing ionic strength of solution because the electrostatic interaction force increased.

show abstract

Section: The Influence Of Ionic Strength On the Electronic Absorption...mentioning

confidence: 99%

The Dependence of Acid-Base Equilbria and Acidity Constants of Congo Red in Buffer Solutions on the Ionic Strength

Hemdan

2024

JCTM

View full text Add to dashboard Cite

show abstract

“…[36] The appearance of isosbestic point in solution between the dyes, this indicates the presence of heterogeneous association between dyes and stoichiometry 1:1. [37] aminoxanthene [38][39][40][41][42][43][44], sulfophthalein [45][46][47], azo dyes [48][49][50], association between acid -base indicators Methyl Orange with Alizarin Yellow GG and Alizarin Yellow G in neutral solution at room temperature , So, the presence of isosbestic point that is assigned to presence monomer-dimmer equilibria state and the ratio of association is 1:1 [51], (Fig. 4).…”

Section: Introduction Definitions and Properties Of Isosbestic Pointmentioning

confidence: 99%

Importance of isosbestic point in spectroscopy: a review

Hemdan¹,

Jebaly²,

Ali³

2024

Journal of Science and Humanities

View full text Add to dashboard Cite

General trends in the development of investigations of isosbestic point, involving the chemical reaction in aqueous solutions are considered. The electronic absorption spectra, fluoresce spectral, equilibrium, and terminological aspects, as well as the possible schemes of formation of two compounds at the same wavelength, are discussed. The contributions of different methods to estimate the concentration of a substance by isosbestic point are analyzed. The interrelationship between the characteristics isosbestic point and phase rule is discussed.

show abstract

Study on An Interaction between Titan Yellow and Orange S Indicators in Water and Ethanol by using Spectroscopy Technique

S. Hemdan,

M. Al Jebaly,

K. Ali

2024

Journal of Science and Humanities

View full text Add to dashboard Cite

Charge transfer complex (CTC) of Orange S (donor) and Titan Yellow (acceptor) has been studied in ethanol, and water solvents at room temperature (20°C) using absorption spectrophotometer. The results indicate that formation of CTC in high polar solvent is high. The stoichiometry of the complex was found to be 1:1 ratio by straight-line method between donor and acceptor with maximum absorption bands and present of isosbestic point suggest this fact. The data are discussed in terms of formation constant (KCT), molar extinction coefficient (εCT), standard free energy (ΔGo), transition energy (ECT), and ionization potential (IP). The formation constant (KCT) for the complex was shown to be dependent upon the polarity of solvents that were used. Electronic absorption spectra, which indicate the CT interaction, associated with proton migration from the acceptor to the donor followed by hydrogen bonding.

show abstract

Time, Concentration, Ionic Strength and Solvents affects on Electronic Absorption Spectra of Association between Acid-Base Indicators

Cited by 3 publications

References 14 publications

The Dependence of Acid-Base Equilbria and Acidity Constants of Congo Red in Buffer Solutions on the Ionic Strength

The Dependence of Acid-Base Equilbria and Acidity Constants of Congo Red in Buffer Solutions on the Ionic Strength

Importance of isosbestic point in spectroscopy: a review

Study on An Interaction between Titan Yellow and Orange S Indicators in Water and Ethanol by using Spectroscopy Technique

Contact Info

Product

Resources

About