All previous posts on the composition of EIS have ignored the CO2 factor. I have explored this and have some interesting information.
Water at room temperature will equalize with the CO2 present in the air. Although air contains about 350 or so ppm of CO2, the water will absorb .58 ppm of CO2 before equalizing with the air. The math to figure this out can be found at http://www.chem.usu.edu/~sbialkow/Classes/3650/Carbonate/Carbonic%20Acid.html and other sites list the concentration as about .5 ppm. Pure water that has equalized with the CO2 in the air will have a pH of 5.65. I have found references that report that normal rain is about 5.7, so this jives pretty well. If you leave water in a glass, the surface will quickly equalize with the air, but diffusion of the CO2 to below the surface is quite slow. So if EIS is produced from water that has stabilized with the air and not stirred, the amount of silver carbonate will be about 3.6 ppm. However if the water is agitated so that the surface layer is continually mixed with the rest of the volume, then as CO2 is consumed by forming a carbonate, more will be absorbed from the air. If this is taken to the limit, then up to 32 ppm of silver carbonate (the solubility limit) can be formed. The unanswered question is just how fast CO2 will be absorbed from the air. I believe there is an easy way to tell with any particular setup. First take distilled water and check the pH. If it is close to 7 then great, if not, then heat it up to boiling to drive off the CO2. Once cooled (without stirring), check the pH and it should be around 7. Be sure to heat in plastic in a microwave, or glass on the stove, any metals will likely add trace contaminates that will affect the pH or act as a buffer invalidating the results. Now place the water into the device for making EIS and run it with NO electrodes. Sample the pH over time and record how fast it changes. This will give the information as to how fast CO2 is absorbed from the air with any particular stirring arrangement. Once we have that information, it should be relatively easy to figure out the concentration of silver carbonate formed by any device when making EIS. Although simply leaving the electrodes, and not running current through them may appear to be the same, any silver oxide on the electrodes can dissolve and affect the pH. Marshall -- The Silver List is a moderated forum for discussing Colloidal Silver. Instructions for unsubscribing are posted at: http://silverlist.org To post, address your message to: silver-list@eskimo.com Silver List archive: http://escribe.com/health/thesilverlist/index.html Address Off-Topic messages to: silver-off-topic-l...@eskimo.com OT Archive: http://escribe.com/health/silverofftopiclist/index.html List maintainer: Mike Devour <mdev...@eskimo.com>
