 Now the last two things we have to discuss here, is the azeotropic mixture and then the Henry's law, okay? So write down next heading, azeotrope, azeotrope write down, it is the, first of all you understand one thing in this particular topic you are not going to get any numerical question, even this is not that much important also, only few things you have to memorize, okay that I will tell you what you need to keep in mind, okay? So write down it is a mixture of, mixture of two or more, two or more liquid in such a ratio in such a ratio, so that its composition, so that its composition cannot be changed, cannot be changed by simple distillation, right? Means you will get a particular composition of the components of the mixture, beyond that the separation is not possible, means you won't get the pure form of any of the component of the mixture, okay? Next let me write down, since, since the composition of the mixture, composition of the mixture is unchanged, mixture is unchanged by distillation, by distillation, hence, hence, hence they are also called as, called as constant boiling mixture, azeotropes are nothing but constant boiling mixture, constant boiling mixture. In this case write down, if the mixture forms, if the mixture forms azeotropic mixture, yeah that you can do Prithee, you can assume that, 2.5 and 100 you can assume, accordingly you find out the number of moles, that you can do, okay? So write down, for azeotropic mixture, for azeotropic mixture, the liquid and vapor composition does not change, the liquid and vapor composition does not change, hence, the separation of component, hence the separation of any of the component in its pure form is not possible, separation of any of the component in its pure form is not possible, okay? This is one thing, so 2, 3 points you need to keep in mind, azeotropic mixtures cannot be separated into its pure form, okay? And they boil at constant temperature, because it is constant boiling mixture, these 2 things you need to memorize, 2 types of azeotropes we have, okay? There are 2 types of azeotropic mixtures and the 2 types we have here is, the first one is positive azeotrope, positive azeotrope, positive azeotrope is possible for those solutions which shows positive deviation from Rawls law, positive deviation from Rawls law, okay? All those solutions which shows positive deviation from Rawls law may behaves as positive azeotrope. For this kind of, we also know that the boiling point of the mixture, write down one more important point, the boiling point of the mixture is less than, is less than any of its, any of its individual component, you need to memorize this, this kind of mixture, azeotropic mixture will have maximum vapor pressure at one composition, what we can say, at one composition, that is azeotropic composition, and this is the azeotropic composition, at one composition, it may have maximum vapor pressure and hence the minimum boiling point, maximum vapor pressure and minimum boiling point and that is why we also call it as minimum boiling azeotrope, since the minimum boiling point we have, so minimum boiling azeotrope. Examples are important, sometimes they also ask examples, suppose water plus ethanol, water plus ethanol, ethanol composition in this mixture is 95.97%, rest is water, so this composition, this plus rest of water gives you positive azeotrope, similarly you see benzene and ethanol, benzene plus ethanol and if ethanol is 32.4%, this and rest of the thing is benzene here, this composition also forms azeotropic, positive azeotropic mixture, acetic acid, acetic acid and toluene, toluene is 72%, so this composition also gives the azeotropic mixture, positive azeotrope, got it, so this examples also you must memorize, the most important thing is this one, maximum vapor pressure and minimum boiling point and minimum boiling azeotrope, done all of you have written this, let me know if you are done, can we move ahead, okay, second type of azeotropic mixture is just opposite of it, that is negative azeotrope, okay, so second type you write down, everything will be exactly opposite here, negative azeotrope, this kind of azeotropic mixture has boiling point more than, more than any of its individual component, just opposite, more than any of its individual component, okay, so at azeotropic mixture and this is shown by all solutions, all solutions which shows negative deviation, negative deviation from Rawls law, negative deviation from Rawls law, okay, this solution at azeotropic mixture, at azeotropic composition it has, it has minimum vapor pressure, minimum vapor pressure and hence maximum boiling point and that is why we also call it as maximum boiling, maximum boiling azeotrope, the other name is this also, maximum boiling azeotrope, example, chloroform and acetone, acetone is 20% and 80% of chloroform forms azeotropic mixture, nitric acid with water 32% azeotropic mixture, okay, these are the examples, so this only theory you need to keep in mind for azeotropic mixture, there are many things in this particular topic which is to understand but in our syllabus we have these much only, you don't require any other things, okay, so this, this is done, the azeotropic mixture is done, now the last thing we are left with is Henry's law, okay, so Henry's law will start after the break, yes