Кислотно-основні властивості систем SO2 – Am (KOH) – Тропеолін OOO – H2O (Am – етаноламіни, морфолін)
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Дата
2022
Науковий керівник
Укладач
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Назва журналу
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E-ISSN
Назва тому
Видавець
Одеський національний університет імені І. І. Мечникова
Анотація
Здійснено спектрофото- та кольорометричне дослідження протеолітичних рівноваг
в системах SO2 – Am (KOH) – Тропеолін OOO (TrOOO) – H2O (Am – етаноламіни,
морфолін) при CTrOOO = 1,12×10–4 М, CAm(KOH) = 0,1 М, T = 293 К. Встановлено
взаємозв’язок кольорометричних функцій (повної колірної відмінності та питомої
колірної відмінності) систем SO2 – Am – TrOOO – H2O із молярною рефракцією Am,
емпіричною функцією pKa – lgPow, що об’єднує їх основність та гідрофільність, константами утворення амонієвих сульфітів та гідросульфітів, характеристиками pH-
(dpH/dpQSO2), редокс (dЕ/dpQSO2) і кондуктометричних (∆κ) кривих титрування водних
розчинів Am газоподібним оксидом сірки (IV).
The study of data on acid-base properties of model systems SO2 – KOH – TrOOO – H2O and SO2 – Am – TrOOO – H2O (TrOOO – tropeoline OOO; Am – diethanolamine (DEA), triethanolamine (TEA), N‑methylmonoethanolamine (MMEA) and morpholine (Mf) at 293 K using pH-, spectrophotometry and colorimetry methods are presented. There is a pronounced isosbestic point at 415 nm in the electronic absorption spectra of the systems SO2– Am –TrOOO– H2O (Am = MMEA, MEA and TEA; pH ≤ 7.5; T = 293 K), which indicates the presence of a dynamic equilibrium between ion-molecular forms. According to the width of the absorption spectra, the bases in the region of 2.0 ≤ pH ≤ 8.0 can be arranged in the following row: MEA > Mf > KOH > DEA > TEA > MMEA. The bases can be arranged in the following rows for the effect on optical density at 490 nm: KOH > Mf ≥ MEA > DEA ≥ TEA (at 5.5 ≤ pH < 9.0); KOH = MEA = Mf > DEA = TEA (at pH < 6.0). According to the values of optical density at 360 nm in the region of 2.0 ≤ pH < 8.5, the bases can be arranged in the following row: Mf > KOH ≥ MEA ≥ DEA > MMEA > TEA. The total color difference (ΔE76) and specific color difference (SCD) values were calculated by colorimetric method as a function of pH. The acid–base dissociation constants in the SO2 – Am (KOH) – TrOOO – H2O systems significantly depend on the structure and physicochemical properties of the organic base and differ significantly from those in the HCl (HClO4, H2SO4) – MEA – TrOOO – H2O systems. The interrelation of colorimetric functions was established (total color difference and specific color difference) of SO2 – Am – TrOOO – H2O systems with molar refraction Am, empirical function pKa – lgPow, which combines the basicity and hydrophilicity of Am, formation constants of ammonium sulfites and hydrosulfites, pH- (dpH/dpQSO2 ), redox- (dЕ/dpQSO2 ) and conductometric (Dk) titration curves of Am aqueous solutions with gaseous sulfur dioxide.
The study of data on acid-base properties of model systems SO2 – KOH – TrOOO – H2O and SO2 – Am – TrOOO – H2O (TrOOO – tropeoline OOO; Am – diethanolamine (DEA), triethanolamine (TEA), N‑methylmonoethanolamine (MMEA) and morpholine (Mf) at 293 K using pH-, spectrophotometry and colorimetry methods are presented. There is a pronounced isosbestic point at 415 nm in the electronic absorption spectra of the systems SO2– Am –TrOOO– H2O (Am = MMEA, MEA and TEA; pH ≤ 7.5; T = 293 K), which indicates the presence of a dynamic equilibrium between ion-molecular forms. According to the width of the absorption spectra, the bases in the region of 2.0 ≤ pH ≤ 8.0 can be arranged in the following row: MEA > Mf > KOH > DEA > TEA > MMEA. The bases can be arranged in the following rows for the effect on optical density at 490 nm: KOH > Mf ≥ MEA > DEA ≥ TEA (at 5.5 ≤ pH < 9.0); KOH = MEA = Mf > DEA = TEA (at pH < 6.0). According to the values of optical density at 360 nm in the region of 2.0 ≤ pH < 8.5, the bases can be arranged in the following row: Mf > KOH ≥ MEA ≥ DEA > MMEA > TEA. The total color difference (ΔE76) and specific color difference (SCD) values were calculated by colorimetric method as a function of pH. The acid–base dissociation constants in the SO2 – Am (KOH) – TrOOO – H2O systems significantly depend on the structure and physicochemical properties of the organic base and differ significantly from those in the HCl (HClO4, H2SO4) – MEA – TrOOO – H2O systems. The interrelation of colorimetric functions was established (total color difference and specific color difference) of SO2 – Am – TrOOO – H2O systems with molar refraction Am, empirical function pKa – lgPow, which combines the basicity and hydrophilicity of Am, formation constants of ammonium sulfites and hydrosulfites, pH- (dpH/dpQSO2 ), redox- (dЕ/dpQSO2 ) and conductometric (Dk) titration curves of Am aqueous solutions with gaseous sulfur dioxide.
Опис
Ключові слова
кольорометрія, етаноламіни, морфолін, водні розчини, оксид сірки (IV), colorimetry, ethanolamines, morpholie, aqueous solutions, sulfur dioxide
Бібліографічний опис
Вісник Одеського національного університету = Odesa National University Herald