----- Original Message ----- From: Keith Addison <[EMAIL PROTECTED]> To: <biofuel@yahoogroups.com> Sent: Monday, September 02, 2002 5:56 PM Subject: [biofuel] Re: Making methanol and lye -
> Hi Paul > > > > It got a bit garbled in transmission, not sure what this character > > > might have been: → > > > >Keith looks like the mystery garble should have been an arrow or > >gives/yields. > > Um, yes. Duh! I don't mind admitting it all looks like fly-shit to > me. Well, not quite, I can follow it up to a point but easily get > lost. Should've guessed the arrows though. Wouldn't worry too much about it Keith its all in house stuff. Each discipline has its own jargon, show me some shorthand or typesetting instructions and I wouldn't have a clue what it was all about. Thats what we are all here for, to pool our knowledge, help each other out and bounce ideas off each other. > >ie : 2 Cl -- ---> Cl2 (gas) + 2 e -- (electrons) chloride ions gas electrons (chloride ions as existing in the ionic state in sodium chloride solution) > >Whether the arrows are oneway or two way I'm not sure in all cases. > >Then below should read > > > > > > ... Consider the electrolysis(application of an electric current via two electrodes) of a water solution of sodium chloride > > (common table salt). At the anode (the negative electrode)the product is, as one might > > expect, chlorine gas. > > > > anode : > > 2 Cl -- ---> Cl2 (gas) + 2 e -- (electrons) > > > > Bubbles of hydrogen form at the cathode;(the positive electrode) the solution immediately surrounding this electrode becomes strongly basic. This evidence indicates that a water molecule rather than a sodium ion is being > > reduced : > > > > cathode : > > 2 H2O + 2 e -- ---> H2 (g) + 2 OH -- > > (quite a bit lost in the translation I'm afraid ,the hydroxide ion should be represented as OH with a superscript minus after it. > > It appears that the water molecule is more readily reduced than the > > Na+ ion. This is entirely reasonable when you consider the addition > > of sodium metal to water results in the spontaneous reaction : > > > > 2 Na (solid) + 2 H2O ---> 2 Na+ + H2 (g) + 2 OH -- Not far wrong about that spontaneous reaction. Teachers at my school used to perform what they called the "Red Sea Experiment". A paper boat would be constructed by one of the students. The boat would be floated on water in a large glass phneumatic trough (fancy words used to describe glass dish about 30cm diam and 15cm high usually used when collecting gas in a gas jar by displacement of water). Some phenolphalein indicator had been mixed into the water previously. This indicator is colourless in acidic or neutral solutions but turns bright pink/purple in alkaline solution. A piece of sodium was then placed in the boat. As the paper absorbed water the boat would sink lower in the water. Bilge water would react with the sodium. The reaction gave off hydrogen and generated much heat causing the hydrogen to burst into flames. This in turn set fire to the boat which would burn to the waterline exposing more of the sodium to water The reaction also created alkaline conditions (the sodium hydroxide produced) within the water causing the phenolphthalein to turn bright pink/purple. Very spectacular when it works right but the problem is the unpredictable burn rate of the sodium. The reaction rate is to a large extent dependent upon the skill of the boat builder. Often the reaction is so fierce that the sodium is liquified and hydrogen forms beneath/within it creats explosions which scatter burning liquid sodium for some distance. Very spectacular unless you happen to be in range. Some of our labs have burn marks on the ceiling as testimony of that little bit too much sodium. Experiment has been banned by head of department for safety reasons. Ah all the excitement has gone out of chemistry these days. We all learn by mistakes especially memorable ones, just so long as we are still around to remenber. Regards Paul Gobert. ------------------------ Yahoo! Groups Sponsor ---------------------~--> 4 DVDs Free +s&p Join Now http://us.click.yahoo.com/pt6YBB/NXiEAA/MVfIAA/FGYolB/TM ---------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
