Chemical Experiments Research Articles

Laying the Groundwork for General Chemistry Experiment Teaching: Exploration and Summary of Assisting Experiment Preparatory Work through Online and Offline Integration

Laying the Groundwork for General Chemistry Experiment Teaching: Exploration and Summary of Assisting Experiment Preparatory Work through Online and Offline Integration

A Green Chemistry Experiment on Electrochemical Synthesis of Benzophenone

A Green Chemistry Experiment on Electrochemical Synthesis of Benzophenone

Comprehensive Organic Chemistry Experiment: Synthesis and Characterization of Triazolopyrimidine Compounds

Comprehensive Organic Chemistry Experiment: Synthesis and Characterization of Triazolopyrimidine Compounds

Innovation and Practice of Polymer Chemistry Experiment Teaching for Non-Polymer Major Students of Chemistry: Taking the Synthesis, Solution Property, Optical Performance and Application of Thermo-Sensitive Polymers as an Example

Innovation and Practice of Polymer Chemistry Experiment Teaching for Non-Polymer Major Students of Chemistry: Taking the Synthesis, Solution Property, Optical Performance and Application of Thermo-Sensitive Polymers as an Example

Preparation of Manganese Oxide and Its Electrochemical Performances in Supercapacitors—A Comprehensive General Chemistry Experiment

Preparation of Manganese Oxide and Its Electrochemical Performances in Supercapacitors—A Comprehensive General Chemistry Experiment

Exploration and Practice of Ideological and Political Reform in Physical Chemistry Experiment

Exploration and Practice of Ideological and Political Reform in Physical Chemistry Experiment

Development of a National First-Class Course of “University Chemistry Experiment” Based on MOOCs

Development of a National First-Class Course of “University Chemistry Experiment” Based on MOOCs

Research on Kinetic and Thermodynamic Transformations of Organic-Inorganic Hybrid Materials for Fluorescent Anti-Counterfeiting Application information: Introducing a Comprehensive Chemistry Experiment

Research on Kinetic and Thermodynamic Transformations of Organic-Inorganic Hybrid Materials for Fluorescent Anti-Counterfeiting Application information: Introducing a Comprehensive Chemistry Experiment

Construction and Exploration of an Online-Offline Blended “Eight-Link” Teaching Method for Physical Chemistry Experiments Based on OBE Concept

Construction and Exploration of an Online-Offline Blended “Eight-Link” Teaching Method for Physical Chemistry Experiments Based on OBE Concept

Incorporating an Interactive Fire Plume‐Rise Model in the DOE's Energy Exascale Earth System Model Version 1 (E3SMv1) and Examining Aerosol Radiative Effect

AbstractThe vertical distribution of biomass burning aerosol (BBA) is important in regulating their impacts on weather and climate. The plume‐rise process affects the injection height of BBA and interacts with the air parcel lifting and cloud processes. However, these processes are not represented in most global climate models. In this study, we replaced the fixed vertical profiles of monthly BBA emissions in the Department of Energy's Energy Exascale Earth System Model version 1 (E3SMv1) with an interactive fire plume‐rise model. The vertical distribution of BBA emissions was calculated as a function of ambient thermodynamic conditions from the host E3SMv1, with distributions of fire sizes and sensible heat fluxes derived from the observations. The maximum fire radiative power (FRP) technique was used to determine the fire size. Scaling‐FRP technique is used to calculate the wildfire heat release. Daily BBA emission, superimposed with a fire diurnal cycle retrieved from the satellite observation, was included in model simulations. The model shows improved agreement with satellite retrievals and in situ measurement during the National Oceanic and Atmospheric Administration Wildfire Experiment for Cloud chemistry, Aerosol absorption, and Nitrogen campaign. The model‐observation comparison demonstrates the importance of the plume‐rise model and fire diurnal cycle assumption in determining the BBA fields. We also find that E3SMv1 with new features produces a larger carbonaceous aerosol burden, leading to 0.13 W m−2 warming at the top of atmosphere compared to the default E3SMv1. This highlights the importance of accurately representing the BBA injection height and indicates a no‐linear nature in the BBA‐induced radiative effect.

Research and Application of Diversified Teaching Methods of Analytical Chemistry Experiment Course in Local Application-oriented Universities

In order to meet the needs of national economic transformation, local undergraduate universities make great efforts to transform into application-oriented universities, and provide application-oriented talents with innovative ability and practical ability for the economic and social development. Starting from the course "Analytical Chemistry Experiment", this paper puts forward diversified teaching methods to stimulate students' interest in learning, so as to cultivate the chemistry major students suitable for the needs of The Times, and serve for the economic and social development.

Learning, Teaching, and Demonstration of Unique Chemistry for the Indonesian Generation at Sanggar Bimbingan Mulia, Kuala Lumpur Malaysia

As a form of concern for the issues faced by the descendants of Indonesian nationals in Malaysia, especially for the Human Resources, we provide the unique theoretical and practical chemistry mentorship for future capability. Sanggar Bimbingan Sungai Mulia 5 is an organization that offers educational services for Indonesian descendants whose citizenship status is still unclear due to administrative reasons. Based on the Chemistry Department UM and Sanggar Bimbingan Mulia cooperation, It is important to enhance the nation's intellectual capacity, especially in ensuring the success of the mandatory 9-year education program. This community service aims to combat illiteracy, in still character education, and prepare students for higher education. The expected outcomes of this program is a unique chemistry Massive Open Online Course (MOOC), a service article published, a service report, and a poster. Our program successfully developed the interest of children to love a simple chemistry experiment and improved for reading and learning through various MOOC, books, and educational materials.

Exploring Experiential Learning: Enhancing Secondary School Chemistry Education Through Practical Engagement and Innovation

Experiential learning, characterized by hands-on engagement and active knowledge construction, has gained prominence in education. This shift is in response to the limitations of traditional teaching methods, which often emphasize passive learning and fail to connect classroom knowledge with practical applications. In the context of secondary school chemistry, experiential learning offers the potential to address these shortcomings, providing students with opportunities for active exploration, concept comprehension, and critical thinking development. This article explores the application of experiential learning techniques in secondary school chemistry classrooms. Experiential learning theories emphasize learner-centered, hands-on engagement to promote active knowledge construction. In chemistry education, experiential methods like experiments and simulations motivate student interest, enhance concept comprehension, and build critical thinking abilities. However, realizing experiential learning's potential requires addressing attendant challenges regarding safety, resources, and assessment. Chemistry experiments carry risks of burns, explosions, and mishaps. Schools in underdeveloped regions need more lab equipment, reagents, and training. Precisely evaluating student knowledge and skill improvements through process-focused experiential activities also poses difficulties. Adaptive virtual learning platforms provide safer and more accessible experiment simulations, enabling personalized learning and detailed performance tracking. Although focusing specifically on chemistry, this essay indicates experiential learning's immense capacity to reinvigorate science education more broadly.

Using machine learning to construct TOMCAT model and occultation measurement-based stratospheric methane (TCOM-CH4) and nitrous oxide (TCOM-N2O) profile data sets

Abstract. Monitoring the atmospheric concentrations of greenhouse gases (GHGs) is crucial to improve our understanding of their climate impact. However, there are no long-term profile data sets of important GHGs that can be used to gain a better insight into the processes controlling their variations in the atmosphere. In this study, we apply corrections to chemical transport model (CTM) output based on profile measurements from two solar occultation instruments: the HALogen Occultation Experiment (HALOE) and the Atmospheric Chemistry Experiment – Fourier Transform Spectrometer (ACE-FTS). The goal is to construct long-term (1991–2021), gap-free stratospheric profile data sets, hereafter referred to as TCOM, for two important GHGs. To estimate the corrections that need to be applied to the CTM profiles, we use the extreme gradient boosting (XGBoost) regression model. For methane (TCOM-CH4), we utilize both HALOE and ACE satellite profile measurements from 1992 to 2018 to train the XGBoost model, while profiles from 2019 to 2021 serve as an independent evaluation data set. As there are no nitrous oxide (N2O) profile measurements for earlier years, we derive XGBoost-derived correction terms to construct TCOM-N2O profiles using only ACE-FTS profiles from the 2004–2018 time period, with profiles from 2019–2021 used for the independent evaluation. Overall, both TCOM-CH4 and TCOM-N2O profiles exhibit excellent agreement with the available satellite-measurement-based data sets. We find that compared to evaluation profiles, biases in TCOM-CH4 and TCOM-N2O are generally less than 10 % and 50 %, respectively, throughout the stratosphere. The daily zonal mean profile data sets, covering altitude (15–60 km) and pressure (300–0.1 hPa) levels, are publicly available via the following links: https://doi.org/10.5281/zenodo.7293740 for TCOM-CH4 (Dhomse, 2022a) and https://doi.org/10.5281/zenodo.7386001 for TCOM-N2O (Dhomse, 2022b).

SynCluster: Reaction Type Clustering and Recommendation Framework for Synthesis Planning.

AI-assisted synthesis planning has emerged as a valuable tool in accelerating synthetic chemistry for the discovery of new drugs and materials. The template-free approach, which showcases superior generalization capabilities, is seen as the mainstream direction in this field. However, it remains unclear whether such an end-to-end approach can achieve problem-solving performance on par with experienced chemists without fully revealing insights into the chemical mechanisms involved. Moreover, there is a lack of unified and chemically inspired frameworks for improving multitask reaction predictions in this area. In this study, we have addressed these challenges by investigating the impact of fine-grained reaction-type labels on multiple downstream tasks and propose a novel framework named SynCluster. This framework incorporates unsupervised clustering cues into the baseline models and identifies plausible chemical subspaces which is compatible with multitask extensions and can serve as model-independent indicators to effectively enhance the performance of multiple downstream tasks. In retrosynthesis prediction, SynCluster achieves significant improvements of 4.1 and 11.0% in top-1 and top-10 prediction accuracy, respectively, compared to the baseline Molecular Transformer, and achieves a notable enhancement of 13.9% in top-10 accuracy when combined with Retroformer. By incorporating simplified molecular-input line-entry system augmentation, our framework achieves higher top-10 accuracy compared to state-of-the-art sequence-based retrosynthesis models and improves over the baseline on the diversity and validity of reactants. SynCluster also achieves 94.9% top-10 accuracy in forward synthesis prediction and 51.5% top-10 Maxfrag accuracy in reagent prediction. Overall, SynCluster provides a fresh perspective with chemical interpretability and reinforcement of domain knowledge in the synthesis design. It offers a promising solution for improving the accuracy and efficiency of AI-assisted synthesis planning and bridges the gap between template-free approaches and the problem-solving abilities of experienced chemists.

Introduction and Characterization of Simple Moisture-Driven Smart Paper for Chemistry Experiment in the Classroom: A Brief Guideline

Introduction and Characterization of Simple Moisture-Driven Smart Paper for Chemistry Experiment in the Classroom: A Brief Guideline

Особливості хімічного експерименту в умовах вимушеного дистанційного навчання

The article focuses on the study of online learning at school, the problems that arose during the school experiment and its impact on the quality of the acquired knowledge. The issue of the quality of knowledge obtained by means of distance learning, the organization of online practical and laboratory work, and the search for methods of diagnosing the quality of knowledge are quite relevant and in demand. The purpose of the study was to establish the level of quality of studying chemistry in the conditions of distance learning and to determine the factors affecting the success of students. The main tasks: to conduct a qualitative observation of the methods of conducting laboratory and practical work (experiments) during online classes and the attitude of students to distance learning and to study the influence of practical and laboratory work (experiments) in chemistry on the quality of knowledge and the identification of students' misconceptions in chemistry that arose during distance learning. It was established that the main common problems for chemistry teachers were finding ways to conduct laboratory and practical work, identifying false (false) ideas and diagnostic tools. According to the results of the student survey, the main disadvantages of distance learning in general and conducting laboratory-practical classes in particular were determined: loss of direct contact, problems with the Internet, lack of light, understanding of the material, lack of skills in working with laboratory equipment, inability to manage time, unfair assessment, as well as the fact that that teachers conduct classes too quickly, leaving no time for questions and discussion. This, obviously, reduces interest in disciplines, understanding of certain concepts and quality of knowledge and level of success. Increasing the share of school and home experiments in chemistry contributed to interest in the subject, understanding of the topic and had a positive effect on the quality of knowledge. According to the results of four knowledge controls, positive dynamics were observed: the average increase was 0.66 points: from 0.2 (for 7th grade students) to 1.1 points (for 11th grade students). The use of conversations and various multi-level tests allows not only to discover which ideas and knowledge students have, but also to understand what actions need to be taken to eliminate them.

Trace-scale extraction of carrier-free tungsten radioisotope as a homolog of Sg using ionic liquid from acid solutions: Kinetic study

This study aimed to find a rapid extraction system for the preparation of a Seaborgium (Sg) aqueous chemistry experiment in the future. A new approach for extraction of 181W tracer as a lighter homolog of (Sg) by ionic liquids is explored. A natural tantalum target was activated by a beam of 9 MeV proton at Cologne University to produce carrier-free 181W. The preliminary batch extraction experiments of the carrier-free 181W from HCl and H2SO4 solutions have been evaluated. Different batch extraction parameters such as feed acidity, diluent type, ionic strength (KCl feed) and reducing agent as a function of time were explored. The obtained results demonstrated that the highest distribution of carrier-free 181W from 0.001 M acidic solutions using the used ionic liquid is observed. A significant rapid kinetic for the extraction of trace-scale using the used ionic liquid is achieved within 5 sec. The preliminary results are necessary to design the upcoming aqueous experiments of Sg. The next goal will be on-line experiments with the centrifuge system SISAK to develop the aqueous chemistry extraction of Sg using the most promising and adequate experimental setup.

Synthesis, Structural Characterization, and Photochemical [2 + 2] Cycloaddition of a Coordination Polymer: Multiweek Inorganic–Organic Chemistry Experiments

Synthesis, Structural Characterization, and Photochemical [2 + 2] Cycloaddition of a Coordination Polymer: Multiweek Inorganic–Organic Chemistry Experiments

Murchison Meteorite Analysis Using Tetramethylammonium Hydroxide (TMAH) Thermochemolysis Under Simulated Sample Analysis at Mars (SAM) Pyrolysis‐Gas Chromatography‐Mass Spectrometry Conditions

AbstractThe Sample Analysis at Mars (SAM) instrument aboard the Curiosity Rover at Gale crater can characterize organic molecules from scooped and drilled samples via pyrolysis of solid materials. In addition, SAM can conduct wet chemistry experiments which enhance the detection of organic molecules bound in macromolecules and convert polar organic compounds into volatile derivatives amenable to gas chromatography‐mass spectrometry analyses. Specifically, N‐tert‐butyldimethylsilyl‐N‐methyltrifluoroacetamide (MTBSTFA) is a silylation reagent whereas tetramethylammonium hydroxide (TMAH) is a thermochemolysis methylation reagent. Shortly after arriving at Mars, the SAM team discovered that at least one of the MTBSFTA cups was leaking, contributing to a continuous background inside SAM with the potential to interfere with future TMAH reactions. Therefore, here we characterized possible interactions between the two reagents to determine byproducts and implications for the detection of indigenous organics. SAM‐like pyrolysis experiments supplemented with flash pyrolysis were accordingly conducted with fragments of the Murchison meteorite as a reference for exogenous organic matter delivered to Mars. Flash TMAH experiments yielded various aromatic acids, dicarboxylic acids, and amino acids while SAM‐like pyrolysis presented mixtures of methylated and non‐methylated compounds due to decreased reaction efficiency at slower ramp rates. All experiments in the presence of simulated MTBSTFA vapor produced pervasive silylated byproducts which co‐elute and obscure the identification of Murchison‐derived compounds. Despite challenges, a significant diversity of pyrolyzates and TMAH derivatives could still be identified in flash pyrolysis in presence of MTBSTFA. However SAM‐like experiments with TMAH and MTBSTFA are hindered by both decreased methylation yields and additional co‐eluting compounds.