We present results of classical trajectory calculations modeling physical adsorption of HCl and ClOH on single-crystal ice under stratospheric conditions. The adsorption energy that we calculate for adsorption of ClOH on ice (-60 kJ/mol) is in excellent agreement with experiment. On the other hand, the calculated surface coverage of single-crystal ice by HCl is orders of magnitude smaller than the values obtained experimentally for adsorption of HCl on vapor-deposited ice. The results suggest that the high surface coverages found in experiments cannot be due to physisorption alone. © 1992 American Chemical Society.
