this video is part of a series of exam question walkthroughs mainly focused on the methods for the AQA a-level chemistry required practical activities this question is looking at required practical activity number five which is how we can separate an organic product from its reaction mixture using distillation before I walk you through how I would approach this question pause the video and have a go at answering it for yourself remember this would be a six mark question so you want to spend about six minutes trying to answer it looking back at previous year's exam papers there hasn't been one in recent years that asked you to write a method for this technique it's much more common to see the exam board giving you poorly set up apparatus and they're asking you to correct the technique but I don't like the idea of there being gaps in this series of videos so this is a question that I think it would be pretty reasonable to ask you about this technique just before I get started in the actual method it's worth saying that of course this question is about distillation and the reason that we can use distillation to separate the butanone in this instance is because it has a different lower boiling point compared to the secondary alcohol that has been synthesized from and the reason for that is that the alcohol has hydrogen bonds between the molecules whereas butanone molecules are only going to have Van Der waals interactions between them which are weaker so therefore it has a lower boiling point to distill this mixture we're going to need a round bottom flask but of course this needs to have a side arm so that we can attach a Lee big condenser and therefore collect the product as it's being distilled off and then into that round bottom flask we're going to add some anti-bumping granules which of course are there to prevent bumping in other words they're going to make sure that any bubbles that are forming are only small bubbles and that we don't have this whole mixture splashing up and going into the condenser we're then going to clamp the round bottom flask above an electric heater and the reason that we're using an electric heater rather than say a Bunsen burner is because it's much safer to not have a naked flame around this reaction where we're using alcohols which are really flammable the next couple of things are where we see a difference between reflux and distillation and often students remember the kind of overall practical that they were doing and they forget which bit is which and this is where we start to see people making mistakes so we want to be including a bung that has a thermometer in it for this because if we're going to distill the product off we need to know what temperature it's at and the height of that thermometer is that it needs to sit just at the junction with the side arm so that the temperature that we're taking is the temperature of the gas as it is boiling off and we want to make sure that that bung is providing a full seal so that we're not just losing our product off into the atmosphere anywhere so then I've mentioned a couple of times that you're going to need to have a labic condenser so that's going to attach onto the sidearm and that's where we're going to be collecting the butanone through and then I probably wouldn't actually write this in a method but it's really important that the water is entering at the bottom and then leaving at the top because if you do that then the condenser is actually going to fill up and it's going to be full of cold water and if you don't do that then there's a good chance that it'll get too warm and your product won't actually condense so as I say I probably wouldn't actually write that into the method but it's one of the things that's come up a couple of times as I'll spot the error that the student has made and let's say they've got their condenser attached to the Taps the wrong way around so once all of that is sorted we can start to apply the heat using the electric heater and then when the temperature is actually correct and it's at the boiling point of butanone then that's when we're going to collect the distillate thank you very much for watching and I hope that you're finding this series of videos about the AQA chemistry required practicals useful in Eurovision if you are finding them useful then don't forget to like And subscribe for more a level chemistry revision videos coming soon thank you