Students’ competence in translating between different types of chemical representations

2020 ◽  
Vol 21 (1) ◽  
pp. 307-330 ◽  
Author(s):  
Vasiliki Gkitzia ◽  
Katerina Salta ◽  
Chryssa Tzougraki
Keyword(s):  
Aqueous Solution ◽  
Solid State ◽  
Chemical Compound ◽  
Chemical Element ◽  
Chemistry Students ◽  
Undergraduate Chemistry ◽  
Different Types ◽  
State Of Matter ◽  
11Th Grade ◽  
Chemical Representations

Meaningful understanding of chemistry, among others, includes the ability of an individual to think simultaneously at macroscopic, submicroscopic and symbolic levels, and this presupposes the competence to translate between different types of chemical representations. In this study, we investigated 11th grade Greek students’ and 3rd year undergraduate chemistry students’ ability to translate chemical representations from one level of chemistry (e.g., submicroscopic) into another (e.g., symbolic) concerning the basic chemical concepts: “chemical element”, “chemical compound”, “aqueous solution” and “solid state of matter”, which have already been taught in earlier grades. We followed a mixed method design in which both quantitative and qualitative research instruments were developed and used. These instruments consisted of multiple choice and open-ended questions, which included real pictures (macroscopic), symbolizations and submicroscopic diagrams. Various representations of the three types were given to the students and they were asked to choose or to construct an equivalent one of a different type. Our results showed that the 11th grade students’ ability to move across the three levels of chemistry is very low, while the 3rd year undergraduate chemistry students’ performance is higher but not satisfactory. In addition, the results obtained from the application of “translation questions” between the three levels of chemistry highlighted many students’ alternative conceptions, some of which still persist among the undergraduate students. The students showed lower performance in translations concerning the concepts “chemical compound” and “aqueous solution” than those concerning the concepts “chemical element” and “solid state of matter”. The students also showed the lowest level of performance in translating the submicroscopic representations into the symbolic ones. Generally, our results indicate that translating between different types of chemical representations is a very challenging task, which depends on students’ conceptual understanding.

Phase Stability and Properties of Superionic PbSnF4 as a Function of the Method of Preparation

1996 ◽  
Vol 453 ◽  
Author(s):  
Raimondo Calandrino ◽  
Anthony Collin ◽  
Georges Denes ◽  
M. Cecilia Madamba ◽  
Juanita M. Parris
Keyword(s):  
Aqueous Solution ◽  
Solid State ◽  
Ambient Temperature ◽  
Ball Milling ◽  
Phase Stability ◽  
Solid State Reactions ◽  
Different Types ◽  
Unit Cells ◽  
Fluorite Type ◽  
The One

AbstractSuperionic PbSnF4 can be prepared using a variety of different methods. It crystallizes in various different unit-cells. All structures are closely related to that of the fluorite type structure, with various degrees of order/disorder and different types of superstructures. Reaction of lead(ll) nitrate and stannous fluoride in water gives highly stressed and highly oriented tetragonal α-PbSnF4, however, in HF/H2O, it gives orthorhombic O-PbSnF4, which is also stressed but less. Reactions of solid α-PbF2 with an aqueous solution of SnF2, in excess SnF2, also gives stressed α-PbSnF4. Solid state reactions of SnF2 and PbF2 give unstressed and much less oriented α-PbSnF4 at 250°C, whereas tetragonal β-PbSnF4 is obtained above 270°C and is quenchable to ambient temperature. At 390°C, cubicy-PbSnF4 is obtained, however, this is not quenchable. Ball milling of o-PbSnF4 gives stressed α-PbSnF4, and ball milling of a- and β-PbSnF4 gives microcrystalline γ-PbSnF4. Annealing the latter gives unstressed and non oriented α-PbSnF4. Stirring a slurry of microcrystalline γ-PbSnF4 in water gives α-PbSnF4 except the one originating from o-PbSnF4, which gives back o-PbSnF4. The texture of these phases, and therefore the macroscopic properties related to it, can be drastically modified by modifying the method of preparation.

Location-thinking, value-thinking, and graphical forms: combining analytical frameworks to analyze inferences made by students when interpreting the points and trends on a reaction coordinate diagram

2021 ◽  
Author(s):  
Alexander P. Parobek ◽  
Patrick M. Chaffin ◽  
Marcy H. Towns
Keyword(s):  
Reaction Rate ◽  
Research Study ◽  
Reaction Rates ◽  
Reaction Coordinate ◽  
Structured Interviews ◽  
Chemistry Students ◽  
Qualitative Research Study ◽  
The Impact ◽  
Analytical Frameworks ◽  
Chemical Representations

Reaction coordinate diagrams (RCDs) are chemical representations widely employed to visualize the thermodynamic and kinetic parameters associated with reactions. Previous research has demonstrated a host of misconceptions students adopt when interpreting the perceived information encoded in RCDs. This qualitative research study explores how general chemistry students interpret points and trends on a RCD and how these interpretations impact their inferences regarding the rate of a chemical reaction. Sixteen students participated in semi-structured interviews in which participants were asked to interpret the points and trends along provided RCDs and to compare relative reaction rates between RCDs. Findings derived from this study demonstrate the diversity of graphical reasoning adopted by students, the impact of students’ interpretations of the x-axis of a RCD on the graphical reasoning employed, and the influence of these ideas on inferences made about reaction rate. Informed by analytical frameworks grounded in the resources framework and the actor-oriented model of transfer, implications for instruction are provided with suggestions for how RCDs may be presented to assist students in recognizing the critical information encoded in these diagrams.

Separation of phenylenediamine isomers by using decamethylcucurbit[5]uril

2021 ◽  
Author(s):  
Long Cao ◽  
Han-Ling Guo ◽  
Rui Lian Lin ◽  
Li-Fei Tian ◽  
Zhi-Hua Zhang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Solid State ◽  
Phenylenediamine Isomers

Using multiple techniques, this work studied the binding behaviors of decamethylcucurbit[5]uril (Me10Q[5]) with o-, m- and p-phenylenediamine (PDA) isomers both in solid state and in aqueous solution. Experimental data indicate...

How well does A-level Mathematics prepare students for the mathematical demands of chemistry degrees?

2016 ◽  
Vol 17 (4) ◽  
pp. 1190-1202 ◽  
Author(s):  
Ellie Darlington ◽  
Jessica Bowyer
Keyword(s):  
First Year ◽  
Chemistry Students ◽  
Undergraduate Chemistry ◽  
Undergraduate Study ◽  
Pure Mathematics ◽  
Entry Requirements ◽  
Good Preparation

332 undergraduate chemistry students were surveyed in order to establish whether they had found A-level Mathematics and/or Further Mathematics to be good preparation for their degree. Perceptions of both subjects were found to be positive, with more than 80% of participants describing Mathematics or Further Mathematics as good preparation. In particular, pure mathematics and mechanics topics were found to be the most useful. Additionally, over 90% of participants who had studied at least AS-level Further Mathematics reported that there was an overlap between the material they encountered at A-level and in the first year of undergraduate study. This indicates that prospective undergraduate chemists would significantly benefit from studying A-level Mathematics, and in particular may benefit from specialising in the study of mechanics, something which will only be possible through the study of Further Mathematics after qualifications are reformed in September 2017. Universities should consequently consider revising their entry requirements or recommendations to applicants.

scholarly journals Electrochemiluminescence Study of Europium (III) Complex with Coumarin3-Carboxylic Acid

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Stefan Lis ◽  
Krzysztof Staninski ◽  
Tomasz Grzyb
Keyword(s):  
Aqueous Solution ◽  
Spectral Analysis ◽  
Energy Transfer ◽  
Solid State ◽  
Carboxylic Acid ◽  
Elemental Analysis ◽  
Aluminium Electrode ◽  
The Eu

The europium (III) complex of coumarin-3-carboxylic acid (C3CA) has been prepared and characterized on the basis of elemental analysis, IR, and emission (photoluminescence and electrochemiluminescence) spectroscopy. The synthesised complex having a formula Eu was photophysically characterized in solution and in the solid state. Electrochemiluminescence, ECL, of the system containing the Eu(III)/C3CA complex was studied using an oxide-covered aluminium electrode. The goal of these studies was to show the possibility of the use of electrochemical excitation of the Eu(III) ion in aqueous solution for emission generation. The generated ECL emission was very weak, and therefore its measurements and spectral analysis were carried out with the use of cut-off filters method. The studies proved a predominate role of the ligand-to-metal energy transfer (LMET) in the generated ECL.

scholarly journals CO2 activation through silylimido and silylamido zirconium hydrides supported on N-donor chelating SBA15 surface ligands

2016 ◽  
Vol 52 (12) ◽  
pp. 2577-2580 ◽  
Author(s):  
Farhan Ahmad Pasha ◽  
Anissa Bendjeriou-Sedjerari ◽  
Edy Abou-Hamad ◽  
Kuo-Wei Huang ◽  
Jean-Marie Basset
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Solid State Nmr ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Co2 Activation ◽  
Functional Theory ◽  
Surface Ligands ◽  
Different Types ◽  
Zirconium Hydrides

Density functional theory calculations and 2D 1H–13C HETCOR solid state NMR spectroscopy prove that CO2 can be used to probe, by its own reactivity, different types of N-donor surface ligands on SBA15-supported ZrIV hydrides: [(Si–O–)(Si–N)[Zr]H] and [(Si–NH–)(Si–X–)[Zr]H2] (XO or NH).

Enhanced adsorption removal of methyl orange from aqueous solution by nanostructured proton-containing δ-MnO2

2015 ◽  
Vol 3 (10) ◽  
pp. 5674-5682 ◽  
Author(s):  
Yan Liu ◽  
Chao Luo ◽  
Jian Sun ◽  
Haizhen Li ◽  
Zebin Sun ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methyl Orange ◽  
Solid State ◽  
Solid State Reaction ◽  
Proton Exchange ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Adsorption Removal ◽  
Homogeneous Precipitation Method ◽  
Enhanced Adsorption

Two nanostructured proton-containing δ-MnO2 (H-δ-MnO2) materials were synthesized through proton exchange for K-containing δ-MnO2 (K-δ-MnO2) nanosheets and nanoparticles prepared by the hydrothermal homogeneous precipitation method and solid-state reaction.

Sign in / Sign up

Export Citation Format

Share Document