Molecular Dynamics Simulation of Hydrochloric Acid Ionization at the Surface of Stratospheric Ice

Molecular dynamics simulations were used to study the acid ionization of hydrochloric acid (HCl) at the basal plane surface of ice at 190 kelvin, as a model for the acid ionization process in Antarctic polar stratospheric clouds (PSCs). Initial conditions for HCl placement within the top bilayer of...

Full description

Saved in:
Bibliographic Details
Published in:Science (American Association for the Advancement of Science) 1996-03, Vol.271 (5255), p.1563-1566
Main Authors: Gertner, Bradley J., Hynes, James T.
Format: Article
Language:English
Subjects:
Atmospheric composition. Chemical and photochemical reactions
Clouds
Computation
Crystal lattices
Earth, ocean, space
Environmental aspects
Exact sciences and technology
External geophysics
Free energy
Hydrochloric acid
Hydrogen
Hydrogen bonds
Ice
Ionization
Ions
Molecules
Ozone layer depletion
Physics of the high neutral atmosphere
Protons
Reactants
Simulation
Solvation
Surface science
Water
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Molecular dynamics simulations were used to study the acid ionization of hydrochloric acid (HCl) at the basal plane surface of ice at 190 kelvin, as a model for the acid ionization process in Antarctic polar stratospheric clouds (PSCs). Initial conditions for HCl placement within the top bilayer of the ice lattice were selected on the basis of relevant dynamic equilibrium adsorption-desorption conditions. Free energy changes calculated for the first step in the stepwise acid ionization mechanism ranged from -5.8 to -6.7 kilocalories per mole for various likely initial conditions. These results indicate that acid ionization is thermodynamically favorable and that this process has important implications for ozone depletion mechanisms involving PSCs.
ISSN:0036-8075
1095-9203
DOI:10.1126/science.271.5255.1563