what are the other factors that affect the boiling point of a particular molecule the first one that we mentioned before is polarity and essentially the more polar your molecule the higher the boiling point is going to be because the stronger the interaction is going to be now the next one is going to be size that the bigger your molecule the higher the boiling point is going to be as well now how is the size make a difference in terms of the boiling point of the molecule well you can have for example a completely nonpolar molecule like this right so methane ethane propane and all the way to decanes are considered non-polar because they're just alkanes and the only difference between them is that we have one carbon two three and so on and so forth now if one were to look at the boiling point in celsius of this particular molecule what you'll find is that the boiling point of methane which is our natural gas is negative 162 celsius so basically it's just a gas at all condition but if we were to have butane which is kind of the lighter that we have on those lighter fluid those have zero degrees celsius boiling point now as you go bigger like hexane which what you'll find in paint thinner the boiling point goes up to about 70 degrees celsius and then if you have decane octane nonin which is what you have for gasoline the boiling point goes above 100 degrees celsius notice that these all all of these molecules are nonpolar right these these all molecules are non-polar but they boil bigger or at a higher temperature compared to water or h2o that's because the size gets bigger so the bigger the size the higher the boiling point is going to be in fact if you look at your candle for example these candles are actually made or made under wax and wax is basically alkene with a change somewhere between 18 to 22 and usually the boiling point is closer to about 200 or 300 degrees celsius depending on how long they are and so that's just kind of an example you can have non-polar molecule but as long as they're big their interaction could get pretty big and the boiling point could get high as well so why is it the case well remember nonpolar molecule have intermittent have dispersion forces right so essentially it's just random fluctuations of the electrons inside the whole compound causes some partial negative and some partial positive that kind of interact weakly from one to the next to the next to the next now each individual interaction might be weak but then if you have a bunch of them throughout the entire molecule it gets stronger so the boiling point of large molecule gets bigger and bigger as well as as the size gets bigger and we're not just this this is true essentially for all molecule suppose that we have we're comparing alcohol here versus just regular alkane well this is still going to have um this size is still going to have an effect on this on on the boiling point we can even look at something that's small like fluorine f2 f2 for example is a gas at room temperature because they're fairly small but if you look at i2 or iodine this is actually a solid at room temperature this is like a nice purple solid this one here is a gaseous compound actually very toxic in any case so those are a couple of things that would affect the boiling point of your material as well as its melting point because both are a proxy for intermolecular force or the relative strength between one to the next now the last one here is geometry and i'm going to leave that discussion once we get to trans and cis configuration on lipids because geometry is going to be specific right so but let me just kind of sum up the geometry in this particular fashion if the molecule packs well the boiling point is going to go up if the molecule doesn't pack well the boiling point is going to go down and that's going to be the three big factor that affects the boiling point and melting point of most compounds that we're going to look at the big one here is going to be polarity and size as well and geometry have some effect although typically a little bit less compared to geometry compared to polarity and size