The Key to the Problem of Reversible Chemical Hydrogen Storage is 12 kJ (mol H2)-1

Author(s):  
Roland Hermann Pawelke

This article outlines a simple theoretical formalism illuminating the boundaries to reversible solid hydrogen storage, based on the ideal gas law and classic equilibrium thermodynamics. A global picture of chemical reversible hydrogen sorption is unveiled, including a thermodynamic explanation of partial reversibility.<br>

2018 ◽  
Author(s):  
Roland Hermann Pawelke

This article outlines a simple theoretical formalism illuminating the boundaries to reversible solid hydrogen storage, based on the ideal gas law and classic equilibrium thermodynamics. A global picture of chemical reversible hydrogen sorption is unveiled, including a thermodynamic explanation of partial reversibility.<br>


2019 ◽  
Author(s):  
Roland Hermann Pawelke

This article outlines a simple theoretical formalism illuminating the boundaries to reversible solid hydrogen storage, based on the ideal gas law and classic equilibrium thermodynamics. A global picture of chemical reversible hydrogen sorption is unveiled, including a thermodynamic explanation of partial reversibility.<br>


2019 ◽  
Author(s):  
Roland Hermann Pawelke

<p>This article outlines a potent theoretical formalism illuminating the boundaries to reversible solid hydrogen storage based on the ideal gas law and classic equilibrium thermodynamics. A global picture of chemical reversible hydrogen sorption is unveiled including a thermodynamic explanation of partial reversibility. This is utilized to elucidate a multitude of issues from metal hydride chemistry: Highlights are why the substitution of a mere 4 mol % Na by K in Ti-doped NaAlH<sub>4</sub> raises the reversible storage capacity by 42 % and elaboration of the reaction pathway in (Rb/K)H-doped Mg(NH<sub>2</sub>)<sub>2</sub>/2LiH. The findings of this work allow for a change of paradigm towards the understanding of reversible chemical energy storage and provide a hitherto missing tool of ample analytic and predictive power, complementary to experiment.</p>


2021 ◽  
Author(s):  
Roland Hermann Pawelke

<p>This article shows up the intrinsic thermodynamic boundaries to reversible mass transfer on basis of the ideal gas law and classic equilibrium thermodynamics in relation to chemical hydrogen storage. In the event, a global picture of reversible chemical hydrogen storage is unveiled, including an explanation of partial reversibility. The findings of this work help to clarify problems of metal hydride chemistry which otherwise are difficult if not impossible to solve in convergent manner, e.g. why the substitution of 4 mol % Na by K in Ti-doped NaAlH<sub>4</sub> raises the reversible storage capacity by 42 % or the way the dopants take effect in (Rb/K)-co-doped Mg(NH<sub>2</sub>)<sub>2</sub>/2LiH. This work's result is of a wider significance since based on two cornerstones of physical chemistry and particularly for the normative role of hydrogen electrodes to electrochemistry.</p>


2019 ◽  
Author(s):  
Roland Hermann Pawelke

<p>This article outlines a potent theoretical formalism illuminating the boundaries to reversible solid hydrogen storage based on the ideal gas law and classic equilibrium thermodynamics. A global picture of chemical reversible hydrogen sorption is unveiled including a thermodynamic explanation of partial reversibility. This is utilized to elucidate a multitude of issues from metal hydride chemistry: Highlights are why the substitution of a mere 4 mol % Na by K in Ti-doped NaAlH<sub>4</sub> raises the reversible storage capacity by 42 % and elaboration of the reaction pathway in (Rb/K)H-doped Mg(NH<sub>2</sub>)<sub>2</sub>/2LiH. The findings of this work allow for a change of paradigm towards the understanding of reversible chemical energy storage and provide a hitherto missing tool of ample analytic and predictive power, complementary to experiment.</p>


2019 ◽  
Author(s):  
Roland Hermann Pawelke

<p>This article outlines a potent theoretical formalism illuminating the boundaries to reversible solid hydrogen storage based on the ideal gas law and classic equilibrium thermodynamics. A global picture of chemical reversible hydrogen sorption is unveiled including a thermodynamic explanation of partial reversibility. This is utilized to elucidate a multitude of issues from metal hydride chemistry: Highlights are why the substitution of a mere 4 mol % Na by K in Ti-doped NaAlH<sub>4</sub> raises the reversible storage capacity by 42 % and elaboration of the reaction pathway in (Rb/K)H-doped Mg(NH<sub>2</sub>)<sub>2</sub>/2LiH. The findings of this work allow for a change of paradigm towards the understanding of reversible chemical energy storage and provide a hitherto missing tool of ample analytic and predictive power, complementary to experiment.</p>


2019 ◽  
Author(s):  
Roland Hermann Pawelke

<p>This article outlines a potent theoretical formalism illuminating the boundaries to reversible solid hydrogen storage based on the ideal gas law and classic equilibrium thermodynamics. A global picture of chemical reversible hydrogen sorption is unveiled including a thermodynamic explanation of partial reversibility. This is utilized to elucidate a multitude of issues from metal hydride chemistry: Highlights are why the substitution of a mere 4 mol % Na by K in Ti-doped NaAlH<sub>4</sub> raises the reversible storage capacity by 42 % and elaboration of the reaction pathway in (Rb/K)H-doped Mg(NH<sub>2</sub>)<sub>2</sub>/2LiH. The findings of this work allow for a change of paradigm towards the understanding of reversible chemical energy storage and provide a hitherto missing tool of ample analytic and predictive power, complementary to experiment.</p>


2021 ◽  
Author(s):  
Roland Hermann Pawelke

<p>This article unveils on basis of the ideal gas law, the atomic conception of matter and classic equilibrium thermodynamics the ideal final regularity of reversible hydrogen mass transfer. This result allows to clarify problems of metal hydride chemistry which otherwise are impossible to understand e.g. why the substitution of 4 mol % Na by K in Ti-doped NaAlH<sub>4</sub> raises the reversible hydrogen capacity by 42 % at no substantial change to thermodynamic reaction parameters or how the dopants take effect in (Rb/K)-co-doped Mg(NH<sub>2</sub>)<sub>2</sub>/2LiH; both cases are discussed in this context. This ideal final regularity is a hitherto missed out superposition of physical chemistry fundamentals and defines the maximum specific energy at distinct conditions: directly for two-phase hydrogen storage methods and indirectly for electrochemical systems due to the normative role of hydrogen electrode potentials.</p>


Author(s):  
Kevin H. Hunter ◽  
Jon-Marc G. Rodriguez ◽  
Nicole M. Becker

Beyond students’ ability to manipulate variables and solve problems, chemistry instructors are also interested in students developing a deeper conceptual understanding of chemistry, that is, engaging in the process of sensemaking. The concept of sensemaking transcends problem-solving and focuses on students recognizing a gap in knowledge and working to construct an explanation that resolves this gap, leading them to “make sense” of a concept. Here, we focus on adapting and applying sensemaking as a framework to analyze three groups of students working through a collaborative gas law activity. The activity was designed around the learning cycle to aid students in constructing the ideal gas law using an interactive simulation. For this analysis, we characterized student discourse using the structural components of the sensemaking epistemic game using a deductive coding scheme. Next, we further analyzed students’ epistemic form by assessing features of the activity and student discourse related to sensemaking: whether the question was framed in a real-world context, the extent of student engagement in robust explanation building, and analysis of written scientific explanations. Our work provides further insight regarding the application and use of the sensemaking framework for analyzing students’ problem solving by providing a framework for inferring the depth with which students engage in the process of sensemaking.


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