I am confused about azeotropes. They are mixtures that cannot change in composition no matter how much distillation you do. A positive azeotrope is one where the boiling point is lower than that of both components in a mixture. A good example is 95.63% ethanol and 4.37% water. This happens because in a positive azeotrope containing X and Y, X and X tend to be together and Y and Y tend to be together.
If X and X tend to be together and Y and Y tend to be together, then why is it that in ethanol and water mixture, you cannot get a more pure ethanol?