Dissolving Salts in Water: Students’ Particulate Explanations of Temperature Changes

Abell, Timothy N.; Bretz, Stacey Lowery

doi:10.1021/acs.jchemed.7b00845

Cited by 16 publications

(33 citation statements)

References 36 publications

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“…Representative inaccurate explanations included the common and well‐documented misconception that energy is released when bonds are broken (Table 2). 60–64 …”

Section: Resultsmentioning

confidence: 99%

“…Representative inaccurate explanations included the common and well-documented misconception that energy is released when bonds are broken ( Table 2). [60][61][62][63][64] Based on the results discussed above, it is possible that many of these students did not consider energy as playing a central role in explaining the denaturation of DNA. It is also possible that some students knew that the idea that energy is required to disrupt hydrogen bonds in the chemistry context, but do not have a deep understanding of how temperature, energy, and noncovalent interactions are associated.…”

Section: Learning Goal 2: Apply Chemistry Core Ideas To Explain a Bmentioning

confidence: 99%

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Students' use of chemistry core ideas to explain the structure and stability of DNA

Allred

Farias

Kararo

et al. 2020

Biochem Molecular Bio Educ

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Students tend to think of their science courses as isolated and unrelated to each other, making it difficult for them to see connections across disciplines. In addition, many existing science assessments target rote memorization and algorithmic problem‐solving skills. Here, we describe the development, implementation, and evaluation of an activity aimed to help students integrate knowledge across introductory chemistry and biology courses. The activity design and evaluation of students' responses were guided by the Framework for K‐12 Science Education as the understanding of core ideas and crosscutting concepts and the development of scientific practices are essential for students at all levels. In this activity, students are asked to use their understanding of noncovalent interactions to explain (a) why the boiling point differs for two pure substances (chemistry phenomenon) and (b) why temperature and base pair composition affects the stability of DNA (biological phenomenon). The activity was implemented at two different institutions (N = 441) in both introductory chemistry and biology courses. Students' overall performance suggests that they can provide sophisticated responses that incorporate their understanding of noncovalent interactions and energy to explain the chemistry phenomenon, but have difficulties integrating the same knowledge to explain the biological phenomenon. Our findings reinforce the notion that students should be provided with opportunities in the classroom to purposefully practice and support the use and integration of knowledge from multiple disciplines. Students' evaluations of the activity indicated that they found it to be interesting and helpful for making connections across disciplines.

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“…Representative inaccurate explanations included the common and well‐documented misconception that energy is released when bonds are broken (Table 2). 60–64 …”

Section: Resultsmentioning

confidence: 99%

Section: Learning Goal 2: Apply Chemistry Core Ideas To Explain a Bmentioning

confidence: 99%

Students' use of chemistry core ideas to explain the structure and stability of DNA

Allred

Farias

Kararo

et al. 2020

Biochem Molecular Bio Educ

View full text Add to dashboard Cite

show abstract

“…This lack of connection to fundamental ideas of physics when chemistry students build explanations has been described by previous authors. 18,51 Although study participants frequently referred to different types of mechanical interactions between particles (e.g., attraction, collisions, intermolecular forces), none of them explicitly associated the presence of a force acting on a particle with particle acceleration or change of speed. Similarly, there was no explicit recognition of the action of a force over a distance (i.e., mechanical work) as the mechanism through which potential energy transforms into kinetic energy or kinetic energy is transferred between colliding particles.…”

Section: ■ Discussionmentioning

confidence: 99%

Exploring Students’ Explanations of Energy Transfer and Transformation

Macrie-Shuck

Talanquer

2020

J. Chem. Educ.

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The ability to build mechanistic explanations of natural phenomena is highly valued in all scientific disciplines, including chemistry. In this paper, we summarize the results of a qualitative study designed to characterize the nature of the mechanistic explanations built by college General Chemistry students when analyzing a physical process involving energy transfer between parts of a system at different temperatures, and a chemical process involving energy transformation and transfer due to chemical bonding. Prior studies have mostly focused on eliciting "what" students think happens in terms of energy transfer when chemical bonds break or form (e.g., energy is absorbed or released) and in this investigation we provide insights into their reasoning about "how" and "why" it happens. Our findings reveal that many students struggle to build sound mechanistic explanations for energy transfer between objects at different temperatures and for energy transformation and transfer during the formation of chemical bonds.

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“…Dissolution of most salts in water is enthalpically negative (∆H < 0) and entropically positive (∆S > 0) and thus a spontaneous process (∆G < 0) [80][81][82][83][84].…”

Section: Thermodynamics Of Desalinationmentioning

confidence: 99%

Looking Beyond Energy Efficiency: An Applied Review of Water Desalination Technologies and an Introduction to Capillary-Driven Desalination

Ahmadvand

Abbasi

Azarfar

et al. 2019

Water

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Most notable emerging water desalination technologies and related publications, as examined by the authors, investigate opportunities to increase energy efficiency of the process. In this paper, the authors reason that improving energy efficiency is only one route to produce more cost-effective potable water with fewer emissions. In fact, the grade of energy that is used to desalinate water plays an equally important role in its economic viability and overall emission reduction. This paper provides a critical review of desalination strategies with emphasis on means of using low-grade energy rather than solely focusing on reaching the thermodynamic energy limit. Herein, it is argued that large-scale commercial desalination technologies have by-and-large reached their engineering potential. They are now mostly limited by the fundamental process design rather than process optimization, which has very limited room for improvement without foundational change to the process itself. The conventional approach toward more energy efficient water desalination is to shift from thermal technologies to reverse osmosis (RO). However, RO suffers from three fundamental issues: (1) it is very sensitive to high-salinity water, (2) it is not suitable for zero liquid discharge and is therefore environmentally challenging, and (3) it is not compatible with low-grade energy. From extensive research and review of existing commercial and lab-scale technologies, the authors propose that a fundamental shift is needed to make water desalination more affordable and economical. Future directions may include novel ideas such as taking advantage of energy localization, surficial/interfacial evaporation, and capillary action. Here, some emerging technologies are discussed along with the viability of incorporating low-grade energy and its economic consequences. Finally, a new process is discussed and characterized for water desalination driven by capillary action. The latter has great significance for using low-grade energy and its substantial potential to generate salinity/blue energy.

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Dissolving Salts in Water: Students’ Particulate Explanations of Temperature Changes

Cited by 16 publications

References 36 publications

Students' use of chemistry core ideas to explain the structure and stability of DNA

Students' use of chemistry core ideas to explain the structure and stability of DNA

Exploring Students’ Explanations of Energy Transfer and Transformation

Looking Beyond Energy Efficiency: An Applied Review of Water Desalination Technologies and an Introduction to Capillary-Driven Desalination

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