The Lord Armstrong's experiment in the view of band theory of liquid water

Alexander Shimkevich

Index: 10.1016/j.chemphys.2018.03.020

Full Text: HTML

Abstract

Liquid water considered in the band theory differs from the ice by localization of electrons in “tails” of the allowed energy bands separated by the wide band gap which defines electrochemical properties of water by means of the allowed energy levels above the middle of the band gap, εH3OεH3O, as electronic donors and below, εOHεOH, as their acceptors. The population of electrons [H3O]/[H3O+][H3O]/[H3O+] and holes [OH]/[OH-][OH]/[OH-] on these levels depends on Fermi level in the band gap. This variable electrochemical potential (as a p-n boundary between the vacant impurity levels and the ones occupied by electrons) becomes the tool for changing physical and chemical properties of liquid water. It turned out that a noticeable shift of Fermi level (more than 1 eV) is possible in the band gap at the expense of an insignificant (|z|<10-10|z|<10-10) deviation of the water composition, H2O1-z,H2O1-z, from the stoichiometric water,H2O.H2O. This deviation is easily homogenized in the bulk liquid. Then, one can introduce into pure water a negative charge [H3O+OH-]∼10-7M[H3O+OH-]∼10-7M or the positive one [H3O++OH]∼10-7M[H3O++OH]∼10-7M by shifting Fermi level up to the donor or acceptor levels in the band gap. These charged molecular pairs (H2O)2- and (H2O)2+ organize the two-way “traffic” in the aqueous “floating bridge” between two glass beakers with the pure liquid water under action of the high dc voltage in the Lord Armstrong's experiment.