Explorations in Computational Science: STELLA Chemistry

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Explorations in Computational Science STELLA
Chemistry
Presenter Robert R. Gotwals, Jr. (Bob2) Shodor
Education Foundation, Inc.
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Workshop Logistics

• Computational Science in chemistry
• Sample Curricula
• Case Studies using STELLA
• Simple kinetics
• Lotka damped/undamped oscillating reactions
• Model with lab-integrated data

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Why Computing in Chemistry?
The underlying physical laws necessary for the
mathematical theory of a large part of physics
and the whole of chemistry are thus completely
known, and the difficulty is only that the exact
application of these laws leads to equations much
too complicated to be soluble. P.A.M. Dirac 1929
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Sample Curricula

• Structure of Matter
• Atomic theory and structure
• Chemical bonding
• Nuclear chemistry
• States of Matter
• Gases, liquids, solids, solutions
• Reactions
• Reaction types
• Stoichiometry
• Equilibrium and kinetics
• Thermodynamics
• Descriptive Chemistry
• Organic chemistry

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Pedagogical Question
Computational (chemistry education)
or
(Computational chemistry) education
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ODEs to STELLA

• Sample set of equations
• dA/dt aA-bB
• dB/dt bB - cC
• dC/dt cC - eC

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Case Study 1 Simple Kinetics

• for the reaction
• A --k1--gt B --k2--gt C
• with A0 3.6 moles
• k1 0.8/minute
• k20.6/minute
• determine the concentrations of A, B, and C over
  a period of 10 minutes
• STELLA tools
• Stock, flow, converter, connector
• Numerical display, graphing tool, and table tool

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Case Study 2 Lotka Damped/Undamped Oscillations

• Application oscillations in chemistry
• Algorithm Lotka differential equations
• Architecture STELLA
• Parameters
• A1.0
• X0 0.15 moles
• Y0 0.01 moles
• Q0 0.0 moles
• k10.3
• k20.6
• k30.4

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Case Study 2 Oscillating Version
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Integrating Data

• Goal build a STELLA model that integrates and
  extrapolates
• Application calibrating a calorimeter
• Data provided on handout
• Determine the cooling factor of the styrofoam
  calorimeter