by Weiqian Liao, Wushuang Lou, Weihua Jin, Shikun Li, Hui Mao and Yihui Bai
Original Research
To explore a greener and safer experimental preparation method for di-n-butyl ether, a modification to the preparation of di-n-butyl ether from 1-butanol was used in this study by replacing the traditional concentrated sulfuric acid as the catalyst with p-toluenesulfonic acid under the guidance of computational calculations. The effects of reaction temperature, catalyst quantity, and other parameters on the reaction were investigated. The catalyst's recovery and reuse were explored. The results reveal that p-toluenesulfonic acid has a catalytic efficiency comparable to that of concentrated sulfuric acid in this experiment, that it is safer and easier to operate, and that it can be recovered and reused using simple procedures, which meets the requirements of green chemistry. The findings of this study may be utilized to enhance the di-n-butyl ether preparation experiment, which can be used in the Organic Chemistry Laboratory course at colleges.
World Journal of Chemical Education. 2022, 10(1), 46-50. DOI: 10.12691/wjce-10-1-6
Pub. Date: February 27, 2022
2214 Views4 Downloads
by Charles Hicks
Original Research
In this work we discuss our experience implementing six hands-on wet-lab experiments designed specifically for at-home use during the pandemic. The experiments cover the concepts of classification of compounds, limiting reagents, spectrophotometry, equilibrium constants, and osmotic pressure. Student survey data on a method of presentation of the experiments using two cameras, and on the effectiveness of demonstration videos of the experimental techniques, which could be viewed by students asynchronously, are presented and discussed. Also discussed are considerations of cost and logistics in the development of hands-on at-home wet-laboratory experiments, and the potential importance of simulations or videos to complement them.
World Journal of Chemical Education. 2022, 10(1), 38-45. DOI: 10.12691/wjce-10-1-5
Pub. Date: March 01, 2022
2640 Views24 Downloads
by Achim Habekost
Original Research
Redox reactions on gold- and silver screen-printed electrodes (SPE) can be monitored electrochemically using cyclic voltammetry (CV) and spectroscopically by electrochemical chemiluminescence (ECL). Alongside conventional anionic ECL, cathionic ECL with in-situ generated, finely-dispersed Au as a co-reagent is also presented. Raman spectroscopy is a powerful technique that can be employed for the detection of ultralow concentrations when promoted by an enhancement of the scattering process. Simple in-situ electrochemical modification of the electrode leads to surface-enhanced Raman intensities.
World Journal of Chemical Education. 2022, 10(1), 23-37. DOI: 10.12691/wjce-10-1-4
Pub. Date: February 11, 2022
9560 Views22 Downloads
by R. Sanjeev, D. A. Padmavathi and V. Jagannadham
Original Research
In chemistry literature it is so far achieved to distinguish o,p-directing groups from m-directing groups purely on the basis of only relative yields of ortho, para and meta electrophilic substituted products in the benzene ring and it is also based on their ability to disturb the pi-electron density at the carbons. It is for the first time in chemistry literature using dipole moment data a linear free energy relationship (LFER), Hammett equation is used to distinguish o,p-directing groups from m-directing groups. This could be achieved by constructing Hammett plots with dipole moments versus Hammett σpara substituent constants for electron donating groups and Hammett σmeta substituent constants for electron withdrawing groups. Good straight lines are obtained with correlation coefficients close to 0.9 with certainly an unmistakable trend.
World Journal of Chemical Education. 2022, 10(1), 20-22. DOI: 10.12691/wjce-10-1-3
Pub. Date: January 03, 2022
2312 Views5 Downloads
by Marit Kristin Leiren and Signe Steinkopf
Original Research
In this chemical education research study, NMR was introduced to a group of 3 students with minor chemistry background. A bench top NMR instrument was used to acquire the 1H-NMR spectra. The 1H-NMR spectra were used to monitor the synthesis of ASA and product purity. The spectrum of the product confirmed its formation, and the spectra of crude and final product allowed the students to observe the elimination of impurities upon recrystallization of the product. Further, the spectrum of the final product was used to quantify the yield through integration of the proton resonances. The use of integrals of the proton resonances for calculation of the yield of ASA is to our knowledge not described elsewhere in undergraduate experiments. A procedure for the synthesis, recording and processing of 1H-NMR spectra, as well as calculation of the yield is reported. This procedure can be implemented by undergraduate or by high school students and might as well be useful for instructors who wants to introduce NMR spectroscopy early in the curriculum of Chemistry. By including an exercise like this, the students get hands on experience to employ advanced technology that might be commonly used in the future, also in Hospital laboratories. Furthermore, it is useful to introduce one of the most demanding and advanced methods in chemistry as early as possible in the curriculum in Chemistry to promote the chemistry career.
World Journal of Chemical Education. 2022, 10(1), 8-19. DOI: 10.12691/wjce-10-1-2
Pub. Date: December 22, 2021
6716 Views24 Downloads
by Ronald P. D’Amelia, Brandon Khanyan and Joseph Mancuso
Original Research
Quantitative nuclear magnetic resonance spectroscopy (qNMR) is a technique used to determine the concentration of one or more analyte within a mixture. Although NMR spectroscopy is typically used to qualitatively determine molecular structure, the quantitative application of NMR extends to concentration determinations and purity assessments. Described herein is an experiment designed to increase awareness of both the qualitative and quantitative applications of NMR spectroscopy that could be integrated into undergraduate analytical and instrumental chemistry laboratory course curriculums. The experiment entails the quantitative analysis of binary long-chain monounsaturated fatty acid mixtures ranging from 0% to 100% in 20% intervals of methyl oleate (MeOl), ethyl oleate (EtOl), propyl oleate (PrOl) and butyl oleate (BuOl) using proton NMR. The goal of the experiment is to determine the structure and weight percent composition of both analytes in each of the mixtures. The results show a strong, linear correlation between the gravimetric compositions and the weight percent compositions found using proton NMR. The experiment supports qNMR as a tool for determining weight percent compositions of mixtures and can be incorporated at the undergraduate chemistry laboratory level.
World Journal of Chemical Education. 2022, 10(1), 1-7. DOI: 10.12691/wjce-10-1-1
Pub. Date: December 09, 2021
5491 Views26 Downloads