Equipment used in an experiment to collect ethanal (acetaldehyde) after the oxidation of ethanol. The ethanol was oxidised from ethanol, an alcohol, by the powerful oxidising agent potassium dichromate. Ethanal is more volatile than ethanol, boiling at a lower temperature, so the gases boiled off during the reaction are largely ethanal. The condensing tube helps to cool and condense the gas back to vapour, and the conical collecting flask is set in ice to speed the process. See clips K004 1216-1219 and 1222 for other stages in this reaction.