Thanks Brian Farrell,
I found the equilibrium constant for that reaction on this site: http://www.h2o2.com/technical-library/physical-chemical-properties/thermodynamic-properties/default.aspx?pid=40&name=Decomposition-Products
But there are no ion size of H2O2. There is only molecular radius (1.32 A) in a literature.
So, dose the ion size in the TEdit mean ion radius?
Thanks.
Jungjin Kim