Heating under reflux sim

What the sim shows

Heat the flask in the water bath (no flame: ethanol and the ester catch fire easily). The mixture boils; its vapour rises into the upright condenser, meets the cold inner tube, turns back to liquid in a ring and drips back into the flask. Nothing escapes, so the mixture can be kept boiling until the reaction has finished. Cooling water goes in at the bottom and out at the top, so the jacket stays full. Oxidation: ethanol + 2[O] → ethanoic acid + water; dichromate(VI) turns from orange to green, manganate(VII) from purple to colourless. On the way, ethanol is first oxidised to ethanal, which boils at 21 °C; reflux sends it back to be oxidised on to the acid. Esterification is reversible (K about 4), so it stops at about 68% of the ethanol here, however long it boils; the few drops of sulfuric acid speed it up and hold a little of the water. We use just enough oxidising agent for all the ethanol. The rates, heat flow, vapour make-up and condenser cooling are this desk's estimates for a school flask; the reactions, colours and boiling points are the lessons'. Volumes are added as if they do not shrink on mixing.

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