acid and base
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Membranes ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 83
Author(s):  
Leyla Gazigil ◽  
Eren Er ◽  
O. Erdem Kestioğlu ◽  
Taner Yonar

In this study, it is aimed to investigate the potential of electrodialysis bipolar membrane (EDBM) systems for the recovery of the concentrate originating from an organized industrial estate (OIE) wastewater treatment system with reverse osmosis (RO). Acids and bases were obtained from a pilot-scale treatment plant as a result of the research. Furthermore, the sustainability and affordability of acids and bases obtained by EDBM systems were investigated. Six cycles were carried out in continuous-flow mode with the EDBM system as batch cycles in the disposal of the concentrate and the production of acids and bases with the EDBM system. For each cycle, the EDBM system was operated for 66, 48, 66, and 80 min, respectively, and the last two cycles were operated for a total of 165 min (70 + 90) with 5 min of waiting. In the EDBM system, a working method was determined such that the cycle flow rate was 180 L/hour, energy to be given to the system was 25 V, and the working pressure was in the range of 0.8–2.5 bar. In the six cycles with the EDBM system, the concentrate, acid and base, conductivity, pH, and pressure increase values were investigated depending on time. Throughout all these studies, the cycles were continued over the products formed in the acid and base chamber. As a result of all the cycles, acid (HCl) production at a level of 1.44% and base (NaOH) production at a level of 2% were obtained.


2022 ◽  
Vol 4 (2) ◽  
Author(s):  
Huan Tian ◽  
Xinxing Yan ◽  
Fu Zhou ◽  
Chuan Xu ◽  
Chao Li ◽  
...  

AbstractA feasibility study was carried out on generation of hydrochloric acid and lithium hydroxide from the simulated lithium chloride solution using EX3B model bipolar membrane electrodialysis (BMED). The influence of a series of process parameters, such as feed concentration, initial acid and base concentration in device component, feed solution volume, and current density were investigated. In addition, the maximum achievable concentrations of HCl and LiOH, the average current efficiency, and specific energy consumption were also studied and compared in this paper to the existing literature. Higher LiCl concentrations in the feed solution were found to be beneficial in increasing the final concentrations of HCl and LiOH, as well as improving current efficiency while decreasing specific energy consumption. However, when its concentration was less than 4 g/L, the membrane stack voltage curve of BMED increased rapidly, attributed to the higher solution resistance. Also low initial concentration of acid and base employed in device component can improve the current efficiency. Increasing of the initial concentration of acid and base solution lowered energy consumption. Moreover, a high current density could rapidly increase HCl and LiOH concentration and enhance water movements of BMED process, but reduced the current efficiency. The maximum achievable concentration of HCl and LiOH generated from 130 g/L LiCl solution were close to 3.24 mol/L and 3.57 mol/L, respectively. In summary, the present study confirmed the feasible application for the generation of HCl and LiOH from simulated lithium chloride solution with BMED.


Author(s):  
Jinyu Tan ◽  
Yixuan Liu ◽  
Mingrui Li ◽  
Hu Li ◽  
Song Yang

Coordination polymers are closely correlated with porous and robust structures. In this work, a variety of novel coordination organophosphate-Hf polymers functionalized with Brønsted/ Lewis acid and base sites were prepared...


Author(s):  
P.B. Savant ◽  
M.A. Qureshi ◽  
Kshirsagar N. ◽  
Manjusha Kareppa ◽  
Avinash B Thalkari ◽  
...  

The oral dosage forms are the most popular way of taking medicine although having some disadvantages like deliberate absorption and thus onset of action is extend. This can be overcome by administrating the drug in a liquid form i.e. effervescent tablet. The research is a formulation of diclofenac sodium as a effervescent tablet by wet granulation method. The bitter taste of the drug are masked by added sweetening agent (lactose, glucose etc.) In the present work we are prepared effervescent tablet in that we are used active drug diclofenac sodium and other active ingredient acid like tartaric acid and base sodium bicarbonate in different concentrations. The formulation of tablet was done by using wet granulation, wet granulation is found to be acceptable method of effervescent tablet formulation. The various pre-formulation studies was performed hardness, weight variation, disintegration, dissolution etc.


2021 ◽  
Vol 5 (4) ◽  
pp. 340-352
Author(s):  
Camalin Bela Sukmaning Fitri* ◽  
Retno Aliyatul Fikroh

Experiments are an important part of the chemistry curriculum. An indicator in the form of a synthesis indicator is commonly used in acid-base materials experiments. The usage of synthetic indicators can result in waste that is both environmentally harmful and costly. The butterfly pea flower is one of the plants that contains anthocyanins, which have the potential to be used as an alternative indication of natural acids and bases. The study aims to determine the acid and base material curriculum and competency indicators, as well as the potential of butterfly pea flower extract as a substitute for synthesis indicators and the practicality of butterfly pea flower extract as a chemical experimental design in SMA/MA. This study employs a descriptive qualitative research method that includes literature review, observation, experimentation, and interviewing. The results showed that the relationship between acid-base materials and experiments was the determination of natural materials as acid-base indicators, the pH of the solution, the identification of acid-base properties, and acid-base titration. The butterfly pea flower indicator was produced from maceration extraction using 96% ethanol as the solvent. The butterfly pea flower indicator gives pink color at pH 1-2, reddish purple at pH 3, light purple at pH 4-5, turquoise at pH 6, bluish green at pH 7, light blue at pH 8-9, green at pH 10, yellowish green at pH 11, greenish yellow at pH 12-13, and yellow at pH 14. The titration step showed that butterfly pea flower indicators could replace synthetic indicators, namely phenolphthalein and methyl orange. Based on the analysis, the butterfly pea flower indicator can be used as an alternative indicator in acid base titration and an alternative experimental design in schools.


Author(s):  
Monica E. McFadden ◽  
Eric V. Patterson ◽  
Keith P. Reber ◽  
Ian W. Gilbert ◽  
John D. Sivey ◽  
...  

Author(s):  
Chandni Chandarana ◽  
Pankaj Kapupara ◽  
Parixit Prajapati

Aims: To study force degradation of aspirin and omeprazole simultaneously by RP-HPLC method Study design: RP-HPLC method was used to measure % degradation. Place and Duration of Study: Study was carried out at center of excellence, G.I.D.C., vapi-396195, Gujarat, India between June 2019 to march 2020. Methodology: A force degradation study of aspirin and omeprazole was carried out simultaneously. The drugs were subjected to various degradation conditions like hydrolysis by acid and base, Oxidative degradation, and thermal degradation study. Results: For acidic condition, the degradation was found to be 32.63 % for aspirin and 61.64 % for omeprazole. For basic condition, the degradation was found to be 10.17 % for aspirin and 4.29 % for omeprazole. By oxidative hydrolysis, the aspirin was degraded by 15.48 % and omeprazole was degraded by 26.38 %. By thermal degradation, 0.37 % degradation was observed for aspirin and 4.32 % degradation for omeprazole. Conclusion: In this proposed method the retention time for drug is less than 8 min, which is less then available method. For omeprazole, strong degradation was observed in acidic conditions and mild in basic hydrolysis conditions. For aspirin, more degradation was observed in basic conditions than acidic hydrolysis. Both drugs were degraded in oxidative conditions using 3% H2O2. Omeprazole degraded more than aspirin by dry heat degradation. The method was successfully applied for the quantitative determination of both Active Pharmaceutical Ingredients.


Author(s):  
Nurul Nazatul Shahizah Mahamd Shobri ◽  
Johari Surif ◽  
Nor Hasniza Ibrahim ◽  
Wimbi Apriwanda Nursiwan ◽  
Muhammad Abd Hadi Bunyamin

Alternative conception or misconception is one of the problems that often be experienced by the students in science subjects including chemistry due to its abstractness and wide scope to be learned. Previous studies found that students often have misconceptions on strength of acid and base topic such as misconception in determining factor that affect the strength of acid and base, differences between strong and weak acid and base as well as the effect of strength of acid and base on conductivity. To overcome these misconceptions, an online teaching and learning module using 5E instructional model was developed. Analysis, Design, Development, Implementation and Evaluation (ADDIE) model is used for research and development. The module used interactive tools and medias to make students being active and understand chemistry well. This module was validated by five experts in term of module objectives, module content, usability, flexibility, learning activities and language aspects with average is ninety percent. The results prove that the module is very good and has high validity. Therefore, the application of online module for acid and base topic based on 5E (Engage, Explore, Explain, Elaborate, Evaluate) model is suitable to be implemented in online teaching and learning process.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Charitha Thambiliyagodage ◽  
Ramanee Wijesekera ◽  
Martin G. Bakker

AbstractNaturally available ilmenite mineral is being used as a starting material to produce titanium based products that have wide applications. Transformation of ilmenite to different titanium based materials by strong and weak acid, and base digestion, is discussed. Effects of temperature, concentration of acid/base, reaction time on dissolution of ilmenite are extensively reviewed. Characterization of the starting materials, intermediates and the products by x-ray diffraction, thermogravimetry, brunauer–emmett–teller surface area analysis, and scanning electron microscopy are presented. Further, advantages and disadvantages associated with the digestion methods are discussed.


Radiocarbon ◽  
2021 ◽  
pp. 1-16
Author(s):  
Fatima Pawełczyk ◽  
Irka Hajdas ◽  
Gino Caspari ◽  
Jegor Blochin ◽  
Timur Sadykov

ABSTRACT Nine burials from Tunnug 1 site in Tuva Republic, which contained human and animal bones as well as remains of wood, were chosen for intercomparison study of preparation methods. Nine human bones, nine animal bones and 11 pieces of wood were prepared. Gelatin extracted from bones was purified using the UF method but the extraction from bones was modified with respect to acid and base treatment. Wood samples were treated as whole using acid-base-acid and cellulose was extracted for comparison. The results confirmed a highly consistent chronology of the sites centered at 200–400 CE, however, a few bones resulted in an offset between ages obtained by different methods. The extraction of cellulose was limited due to the poor preservation of wood. Our results highlight problems of dating poorly preserved bones and wood.


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