Keywords: Distillation of dry and oxygen-free toluene.jpg toluene from sodium-benzophenone desiccant Glassware are under a slight positive nitrogen pressure from the side-arm of the receiving Schlenk flask to prevent oxygen contamination Note that this is not a closed system - the nitrogen supply is connected to an oil bubbler not in picture to prevent overpressure <p>Photo taken on 6 Sep 2006 <p>Keywords distillation toluene sodium benzophenone desiccant Gallery <gallery><gallery> Image Benzophenone bottle jpg A bottle of benzophenone by Lancaster Image Toluene with sodium-benzophenone jpg Toluene is refluxed with and benzophenone to produce dry oxygen-free toluene Image Toluene with sodium-benzophenone - brown jpg The mixture is still not blue yet indicating that the reaction is not complete Image Toluene with sodium-benzophenone - intense blue jpg The intense blue coloration due to the benzophenone ketyl radical shows that the toluene is considered free of air and moisture Image Distillation of dry and oxygen-free toluene jpg After the toluene has been thoroughly dried by the sodium and benzophenone it is distilled at atmospheric pressure under a slight positive pressure of nitrogen to prevent contamination by air into the receiving Schlenk flask </gallery> Transferred from http //en wikipedia org en wikipedia; transferred to Commons by User Liftarn using http //tools wikimedia de/~magnus/commonshelper php CommonsHelper 2006-09-05 Original uploader was Rifleman 82 at http //en wikipedia org en wikipedia Released into the public domain by the author en wikipedia Rifleman 82 Original upload log page en wikipedia Distillation_of_dry_and_oxygen-free_toluene jpg 2006-09-05 16 23 Rifleman 82 1600×1200× 391204 bytes <nowiki>Distillation of dry and oxygen-free toluene from sodium-benzophenone desiccant Glassware are under a slight positive nitrogen pressure from the side-arm of the receiving Schlenk flask to prevent oxygen contamination </nowiki> Laboratory distillation apparatus Benzophenone |