Conductimetric Titrations: A Predict−Observe−Explain Activity for General Chemistry

Smith, Kendric C.; Edionwe, Etinosa; Michel, Bayyinah

doi:10.1021/ed100538q

Cited by 23 publications

(17 citation statements)

References 36 publications

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“…The conductometric titration curve obtained for the PPC sample showed a typical conductometric profile for proteins, where the titration of both carboxylic acid and amine groups in the material are revealed as two transition regions (Figure 5). As described by Xu et al, 45,46 the first region reflects the neutralization of the H + from the −COOH, and the second region reflects the neutralization of H + in the −NH 3 + , both weak acids. The PPC/ SA sample showed, on the other hand, only one region in the conductometric plot, which resembled the behavior observed for titrated cellulose nanocrystals.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Novel Sustainable Superabsorbents: A One-Pot Method for Functionalization of Side-Stream Potato Proteins

Capezza

Glad

Özeren

et al. 2019

ACS Sustainable Chem. Eng.

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The functionalization of inexpensive potato protein concentrate (PPC) is presented as a simple and easily scalable method to produce bio-based superabsorbent powders. Five nontoxic acylating agents were evaluated at different reaction temperatures for solvent-free acylation of the protein. The best results were obtained for succinic anhydride (SA) and a reaction temperature of 140 °C. These conditions resulted in efficient functionalization that provided formation of a useful network, which allowed high uptake of fluids and little material disintegration during the uptake, that is, due to protein hydrolysis during the functionalization. The SA-acylated PPC showed increased water and saline swelling capacities of 600 and 60%, respectively, as compared to untreated PPC. The acylated potato protein also showed a saline liquid holding capacity of approximately 50% after centrifugation at 1230 rpm for 3 min, as well as a significant blood swelling capacity of 530%. This blood swelling represents more than 50% of that of a commercial fossil-based superabsorbent (SAP) used for blood absorption in sanitary health products. The swelling properties of these inexpensive protein-based acylated materials highlight their potential as sustainable SAP materials (from industrial side-streams) in applications such as daily care products that are currently dominated by fossil-based SAPs.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Novel Sustainable Superabsorbents: A One-Pot Method for Functionalization of Side-Stream Potato Proteins

Capezza

Glad

Özeren

et al. 2019

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…Several studies support the effectiveness of inquiry-based learning implemented by different strategies [45], such as those based on the 5E (engage, explore, explain, elaborate, and evaluate) model [46] and the POE strategy [47]. Under the POE strategy, when students encounter a cognitive conflict between the predictions regarding a scientific topic and the observation results, the teacher can provide them with appropriate media, guide them to make observations from different perspectives, and encourage them to present evidence and explanations for them to make predictions [48,49].…”

Section: Inquiry-based Learningmentioning

confidence: 99%

Development of a Virtual Wetland Ecological System Using VR 360° Panoramic Technology for Environmental Education

Chu

Tarng

2021

Land

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In this study, the VR 360° panoramic technology is used to develop a virtual wetland ecological system for applications in environmental education. The system provides a virtual wetland environment for autonomous exploration, where the user can conduct inquiry-based learning by cardboard VR to obtain essential information and concepts in ecological protection. It contains the learning contents of wetland ecology and creatures in Hsinchu coastal areas, northern Taiwan. To investigate the learning effectiveness of the VR system, we recruited 42 seventh graders as participants and divided them evenly into two groups. The experimental group used the virtual wetland ecological system for learning and the control group learned with conventional teaching materials. The differences of the experimental results indicated: (1) the experimental group showed a high degree of satisfaction after using the virtual wetland ecological system; (2) the learning achievement of the experimental group was significantly higher than that of the control group; (3) the learning motivation of the experimental group was significantly higher than that of the control group. The virtual wetland ecological system can enhance the learning effectiveness and learning motivation using low-cost cardboard glasses, so it is a suitable tool for promoting environmental education in remote areas.

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“…Next, they describe what they observe during the demonstration, and, afterward, they explain their observations and reconcile any discrepancy between their predictions and observations. This technique has been frequently investigated over the years [15,16,[22][23][24][25][26][27][28][29][30][31][32]. Therefore, it is a known approach in science education research, but the implementation is lacking.…”

Section: Theoretical Frameworkmentioning

confidence: 99%

Two Design Principles for the Design of Demonstrations to Enhance Structure–Property Reasoning

et al. 2021

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Structure–property reasoning (SPR) is one of the most important aims of chemistry education but is seldom explicitly taught, and students find structure–property reasoning difficult. This study assessed two design principles for the development of structure–property reasoning in the context of demonstrations: (1) use of a POE task (predict–observe–explain) and (2) use of the domain-specific particle perspective, both to increase student engagement and to scaffold micro-level modeling. The aim of the demonstration series was to teach structure–property reasoning more explicitly to pre-university students (aged 15–16). Demonstrations pertained to the properties of metals, salts and molecular compounds. The SPR instrument was used as a pretest and posttest in order to gain insight into the effects on structure–property reasoning. In addition, one student (Sally) was followed closely to see how her structure–property reasoning evolved throughout the demonstrations. Results show that after the demonstrations students were more aware of the structure models at the micro-level. The students also knew and understood more chemical concepts needed for structure–property reasoning. Sally’s qualitative data additionally showed how she made interesting progress in modeling micro-level chemical structures. As we used conventional demonstrations as a starting point for design, this could well serve as a practical tool for teachers to redesign their existing demonstrations.

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Conductimetric Titrations: A Predict−Observe−Explain Activity for General Chemistry

Cited by 23 publications

References 36 publications

Novel Sustainable Superabsorbents: A One-Pot Method for Functionalization of Side-Stream Potato Proteins

Novel Sustainable Superabsorbents: A One-Pot Method for Functionalization of Side-Stream Potato Proteins

Development of a Virtual Wetland Ecological System Using VR 360° Panoramic Technology for Environmental Education

Two Design Principles for the Design of Demonstrations to Enhance Structure–Property Reasoning

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