In a message dated 6/22/01 5:19:32 PM EST, [email protected] writes: << According to Bob's own analysis, he got about 10 ppm of silver and 1.6 ppm of HNO3. Therefore, the CO2 does not seem to eliminate the nitrates.
Frank: Even when air is intentionally passed "through an electric arc in such a way that the hot gas mixture was cooled very rapidly, thus 'freezing' the high temperature equilibrium mixture" (Linus Pauling, College Chemistry, 2nd Ed., 1955 publisher: W.H. Freeman & Co. San Francisco), the slightly endothermic reaction, (1) N2 + O2 --------------> 2NO is quite sluggish. For example, the yield at 1500 C is only 0.4%, and at 3000 C it rises to only 5%. By using heavy silver electrodes so that the arc tip dissipates heat rapidly, reaction (1) should be inhibited by a lower plasma temperature. In addition, using an argon blanket will further reduce nitric oxide production by decreasing the partial pressures of nitrogen and oxygen to much lower levels than that corresponding to air. Another way to reduce the yield of NO is to recognize that **minimizing** the production rate of NO is only half the problem, it's just as important to **maximize** the production rate of CS. By changing the electrode configuration such that the arc temperature is high over a very small surface area, it is possible to "sputter" silver off the electrode tip while still minimizing NO production, thus increasing the silver/NO ratio many times. Now let's look closely at the generation of nitric acid to see if we can reach any firm conclusions. Assuming this nitric oxide is allowed to cool slowly enough to form nitrogen dioxide, and (at the PPM levels of nitrate reported by Bob) that excess oxygen is present, nitric acid will be produced by reaction (2). (2) 2NO2 + H2O + 1/2)O2 ------------> 2HNO3 Since Bob reports his nitrate analyses at NO3, (not nitric acid as you show above), let's calculate how much H+ has been generated by reaction (2). 1.6 mg/l NO3 is equivalent to 0.0258 millimoles of H+. The pH of such a solution is 4.6 (negative log of 2.58 X 10^-5 moles/L), similar to the pH usually found in CS prepared from the HVAC arc method (typical pH = 3 - 4), but I have some doubt that such a pH can explain the disappearance of silver particulate particularly since Bob has found a Tyndall in many of his samples, presumably including some that have been on the shelf for a while. Perhaps Bob would like to add his thoughts. Roger Roger -- The silver-list is a moderated forum for discussion of colloidal silver. To join or quit silver-list or silver-digest send an e-mail message to: [email protected] -or- [email protected] with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: [email protected] Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <[email protected]>
