THE DEPENDENCE OF ACID-BASE EQUILBRIA AND ACIDITY CONSTANTS OF CONGO RED IN BUFFER SOLUTIONS ON THE IONIC STRENGTH

Q3 Engineering
Sokaina Hemdan
{"title":"THE DEPENDENCE OF ACID-BASE EQUILBRIA AND ACIDITY CONSTANTS OF CONGO RED IN BUFFER SOLUTIONS ON THE IONIC STRENGTH","authors":"Sokaina Hemdan","doi":"10.59957/jctm.v59.i3.2024.2","DOIUrl":null,"url":null,"abstract":"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.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"4 6","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Chemical Technology and Metallurgy","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.59957/jctm.v59.i3.2024.2","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Engineering","Score":null,"Total":0}
引用次数: 0

Abstract

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.
缓冲溶液中刚果红的酸碱平衡和酸度常数与离子强度的关系
本研究考察了刚果红乙醇水溶液在室温 25oC 和不同离子强度 0.05、0.1、0.3 和 0.5 KCl mol L-1 的各种缓冲溶液中的分光光度法。刚果红的酸度常数由三种不同的方法估算得出。在 pH 值为 2 - 4 和 4 - 6 时,观察到两个质子化阶段,即氨基和偶氮基团的质子化。刚果红的吸收光谱与溶液的离子强度有关,随着离子强度的增加,吸收光谱的形状和强度也会发生变化。因此,随着离子强度的增加,酸碱平衡向更高的 pH 值移动。此外,酸度常数也受到离子强度的影响,随着溶液离子强度的增加,酸度常数会降低,因为静电相互作用力增加了。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Journal of Chemical Technology and Metallurgy
Journal of Chemical Technology and Metallurgy Engineering-Industrial and Manufacturing Engineering
CiteScore
1.40
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信