Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site mit-eddie.UUCP Path: utzoo!linus!philabs!cmcl2!harvard!think!mit-eddie!jbs From: jbs@mit-eddie.UUCP (Jeff Siegal) Newsgroups: net.sci Subject: Re: Question about Electricity Message-ID: <333@mit-eddie.UUCP> Date: Thu, 7-Nov-85 00:57:21 EST Article-I.D.: mit-eddi.333 Posted: Thu Nov 7 00:57:21 1985 Date-Received: Fri, 8-Nov-85 21:23:31 EST References: <621@hlwpc.UUCP> <662@petrus.UUCP> <714@alberta.UUCP> <2358@ukma.UUCP> Reply-To: jbs@mit-eddie.UUCP (Jeff Siegal) Distribution: net Organization: MIT, Cambridge, MA Lines: 18 Keywords: water, electricity In article <2358@ukma.UUCP> slg@ukma.UUCP (Sean Gilley) writes: > > > Pure water (H2O) does not conduct electricity. The reason you need to >be careful with electricity around water is that the minerals in solution >within the water are conductors. > > This is not quite correct. Pure water (H2O) DOES conduct elecricity. However, the conductivity is sufficiently low that it can often be ignored. What causes aqueous solutions to be conductive is the ions which present in the solution. If I remember correctly, water is itself partially ionized. The concentration of H+ (and other complexes, H3O+, etc.) is 1 x 10**-7 mole/L. The pH is defined as - LOG10(concentration of H+ ions). Thus the pH of pure water is 7. Jeff Siegal - MIT EECS (jbs@mit-eddie)