Enhancing learning in the laboratory: Identifying and promoting best practice in the professional development of demonstrators

A critical component of science and engineering degrees are the laboratory classes. These laboratory classes are also one of the most neglected areas for the professional development of the laboratory demonstrators, who are usually senior students (Honours, Masters or PhD) with little or no teaching experience. In response to concerns about the quality of instruction in laboratories, a Laboratory Demonstrators Professional Development Program (LDPDP) was developed at Curtin to enhance the teaching skills of laboratory demonstrators.1 A key focus of this LDPDP is to develop demonstrators who are proactive in enhancing the positive learning experiences of their students. An OLT 2015 National Teaching Fellowship aimed to improve the learning experience of students in laboratories through the enhanced professional skills of demonstrators. Following consultation with national and international scholars in institutions that have established PD programs, a refined LDPDP is being developed and disseminated across Australia via local facilitators. To increase the profile and benefits of quality laboratory teaching, a framework for an evidence-based "Certificate of Laboratory Demonstrating" will also be developed. This presentation will report on the progress thus far, which includes the running workshops at eight institutions. Reports from local facilitators will be included. References 1. Mocerino M, Zadnik M, Yeo S, (2015) "Enhancing students' learning in laboratories through professional development of teaching assistants" EC2E2N NewsLetter 2015 – Special Edition: Chemistry Teaching and Learning. http://www.ec2e2n.info/news/2015/1601_20150

A brief review of Cn-symmetric calixarenes and resorcinarenes

Calixarene and resorcinarene macrocycles are renowned for their ability to form inclusion complexes or act as molecular scaffolds. The addition of chirality to these non-planar molecules is an exciting enhancement of their already robust potential, offering much promise as ligands for chiral catalysis and enantioselective separations. Chiral calixarenes can be produced by the attachment of a chiral moiety or by the placement of an achiral functionality on the macrocyclic structure so as to render it asymmetric. The latter method is particularly intriguing, often resulting in molecules which have Cn dissymmetry. This review describes examples of the Cn-dissymmetric calixarenes and resorcinarenes prepared to date and discusses aspects of their chirality, including their pictorial and written descriptors

Microscopic observation of solid-liquid reaction: A novel laboratory approach to teaching rate of reaction

The importance of observation in science and science education has triggered this laboratory development study that investigated the value of an observation kit as a new approach to teaching rate of reaction in general chemistry class. The kit consists of a digital microscope, a “chemical reactor”, and a tailor-made computer application and was used to video-record a solid-liquid reaction and to produce a series of two dimensional solid images that indicate the extent of reaction. The two dimensional image areas were calculated by the computer application by assuming that the image area was directly proportional to the solid mass from which a plot of mass versus time could be obtained. These steps have been tested to solid (zinc, iron, calcium carbonate, and magnesium oxide)-liquid (acid solution reaction systems. Reaction of solid magnesium oxide with nitric acid solution resulted in the best images which were transferable to a plot of solid magnesium oxide mass as a function of time. This was used to explain rate of reaction concepts including average, instantaneous, and initial rate. Furthermore, the effect of concentration on reaction rate could also be explained. The generated data allows students to clearly and repeatedly visualize a solid-liquid reaction and relates rates of reaction concepts. The observation kit also allows teachers and students to extend its application into inquiry based experiments. © 2017, Gadjah Mada University. All rights reserved

The impact of the lanthanide contraction on the structure of complexes of a calix[4]arene trisamide

The syntheses of samarium, holmium, and ytterbium complexes of a tris-amide calix[4]arene are described, and the resulting structures are compared with the previously reported gadolinium complex. The syntheses involved the reaction of 5,11,17,23-tetra-tert-butyl-24-hydroxy-26,27,28- tris(diethylcarbamoylmethoxy)calix[4]arene with the appropriate lanthanide picrate hydrate. Structural studies demonstrated that a picrate anion acts as a quasi-bidentate ligand with Sm (and Gd), is unidentate in the Ho complex, but is found in the second coordination sphere for the smallest lanthanide cation (Yb) investigated

Patterns demonstrated by college students in drawings regarding sodium chloride and implications for the classroom

One of the important aspects in Chemistry Education is to enable students to represent explanatory models at the submicro level, which are difficult for students to understand (Davidowitz & Chittleborough, 2009; Kelly et al., 2010, Locatelli & Davidowitz, 2021, for example). However, students’ understanding of submicro entities is necessary to explain the behaviour of macroscopic phenomena (Davidowitz & Chittleborough, 2009), as well as to make the transition between the three levels of representation: macro, symbolic, and submicro levels. Taking this into account, it is essential to research possible representation patterns demonstrated by students when representing chemical substances, as well as their reactions. This study presents preliminary results of ongoing research, considering 18 Brazilian undergraduate students, being first-year college students. The activity consisted of asking students to represent kitchen salt, a student-generated drawing, in the best way for them, without consulting any material beforehand. Next, the drawings were analyzed to find possible misconceptions in chemistry. The findings showed that few students represented the macro level (5/18), most considered the symbolic level (15/18), and for the submicro level, only 6 considered ionic clusters and 11 of them considered salt as formed by “molecules”. Despite the limitation of the considered sample, it can bring implications for the teaching of this topic, in which the teacher will be able to think and propose metavisual activities that allow the revision of chemical concepts (Locatelli & Davidowitz, 2021). For example, to review the incorrect designation “molecule” of salt, as well as proper access to representational levels. In line with this, Park and colleagues (2020) have suggested that teachers can consider the different levels of representation (in our case, chemistry) with the aim that students can build scientific explanations using their generated drawings. Acknowledgments to FAPESP for grant #2022/16395-3. REFERENCES Davidowitz, B., & Chittleborough, G. (2009). Linking the Macroscopic and Sub-microscopic Levels: Diagrams. In: Gilbert, J.K., Treagust, D. (eds) Multiple Representations in Chemical Education. Models and Modeling in Science Education, vol 4. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-8872-8_9   Kelly R. M., Barrera J. H., & Mohamed S. C. (2010), An analysis of undergraduate general chemistry students’ misconceptions of the submicroscopic level of precipitation reactions. Journal of Chemical Education, 87(1), 113–118. https://doi.org/10.1021/ed800011a Locatelli, S., & Davidowitz, B. (2021). Using metavisualization to revise an explanatory model regarding a chemical reaction between ions. Chemistry Education Research and Practice, 22, 382–395. https://doi.org/10.1039/D0RP00339E  Park, J., Chang, J., Tang, K., Treagust, D., & Won, M. (2020): Sequential patterns of students’ drawing in constructing scientific explanations: focusing on the interplay among three levels of pictorial representation. International Journal of Science Education, 42(5), 677-702 https://doi.org/10.1080/09500693.2020.172435

Understanding the Rate of Acid Reactions: Comparison Between Pre-Service Teachers and Grade 10 Students

A two-tier multiple choice diagnostic instrument on the stoichiometry and rate of acid reactions was administered to 611 Grade 10 students and 171 pre-service teachers. The results showed that the Grade 10 students and preservice teachers held alternative conceptions related to the properties of different acids affecting their rates of reaction, and the particles in the resulting mixtures at the end of the reactions. The study stresses the importance of identifying and clarifying the pre-service teachers' understanding of the concepts that they will teach as this may have consequences on their future students' learning of chemistry

Bio-Inspired Calix[4]arene Additives for Crystal Growth Modification of Inorganic Materials

Crystal growth of inorganic materials, calcium carbonate, barium sulfate and calcium oxalate, was studied in the presence of calix[4]arene additives functionalized with aspartic or glutamic acids at the lower rim. The additives were synthesized by reaction of the appropriate amino acid ester with 5,11,17,23-tetra-tert-butyl-25,-26,27,28-tetrakis(chlorocarbonylmethoxy)calix[4]arene, followed by controlled hydrolysis of the ester groups. Both additives inhibited the nucleation and growth of calcium carbonate but induced different changes in calcite morphology. The aspartic acid derivative was the more potent barium sulfate inhibitor at low concentrations, with comparable performance at higher levels. Both additives induced a polycrystalline barite precipitate. The aspartic acid functionalized calixarene also stabilized calcium oxalate dihydrate at low additive concentrations, whereas the glutamic acid derivative induced morphological changes in calcium oxalate monohydrate

C4 Dissymmetric resorcinarene derivatives: synthesis, crystal structure and micelle formation

The synthesis of a C4 dissymmetric resorcinarene tetracarboxylic acid derivative and determination of its critical micelle concentration is reported. The tetrahydroxy derivative was prepared by reduction of the tetra-acid. The low-temperature single crystal X-ray structure of the methyl ester derivative of the tetra-acid is also reported. This crystallised with two independent molecules of similar boat (flattened cone) conformation within the asymmetric unit

An investigation of the place of inquiry-based learning in chemistry laboratories in senior secondary school and first-year university

One of the most important aspects of science education is understanding how evidence, data, and models explain the natural world. Laboratory work strengthens this understanding by linking content knowledge to science practices and promoting student inquiry. Inquiry within chemistry education is generally taught through laboratory experiments, ranging from traditional, guided inquiry and open inquiry experiments (Furtak et al., 2012). This poster will look at the preliminary results from 152 undergraduate Curtin University students who completed year 11 chemistry. A questionnaire derived from five Likert scales (Chatterjee et al., 2009; Cheung, 2011; Fraser et al., 1993) was used to understand students' past experiences with inquiry types and if changes should be made to the level taught at year 11. The results showed strong support for guided inquiry laboratories compared to open and procedural laboratories. While guided inquiry was favoured, students acknowledged that conducting procedural experiments better develops practical skills. Additionally, participants had to match the most frequent type of inquiry to a scenario with students struggling to decide between open and guided inquiry; students more uniformly identified procedural laboratories.  REFERENCES Chatterjee, S., Williamson, V. M., McCann, K., & Peck, M. L. (2009). Surveying students' attitudes and perceptions toward guided-inquiry and open-inquiry laboratories. Journal of Chemical Education, 86(12), 1427. https://doi.org/10.1021/ed086p1427 Cheung, D. (2011). Teacher beliefs about implementing guided-inquiry laboratory experiments for secondary school chemistry. Journal of Chemical Education, 88(11), 1462-1468. https://doi.org/10.1021/ed1008409 Fraser, B. J., McRobbie, C. J., & Giddings, G. J. (1993). Development and cross-national validation of a laboratory classroom environment instrument for senior high school science. Science Education, 77(1), 1-24. https://doi.org/https://doi.org/10.1002/sce.3730770102 Furtak, E. M., Seidel, T., Iverson, H., & Briggs, D. C. (2012). Experimental and quasi-experimental studies of inquiry-based science teaching: A meta-analysis. Review of Educational Research, 82(3), 300-329. https://doi.org/10.3102/003465431245720