How many boiling points does a mixture of liquids have?

Let's say I have a mixture of two miscible liquids. I want to get the liquids by fractional/pure distillation. My textbook says a mixture boils over a range of temperatures. On the contrary, another book I read says a mixture has only one boiling point and that the liquid with a lower boiling point adds more of itself to the mixture. I am wondering which of those is correct and will work with distillation.

• The mixture boils over a range of temperatures. The lowest point of that range is called the boiling point. – Ivan Neretin May 14 at 11:58
• There is too few information to anticipate if a separation of the two liquids by distillation may be achieved, or not. Depending on their mutual interaction, perhaps they form an azeotrope and you only reach a maximal concentration of A in B (c /= 100%), e.g., HCl/water. – Buttonwood May 14 at 12:12
• The actual mixture (at a given x) has one defined boiling point (at given P) but as boiling change composition the boiling occurs over a range of T. – Alchimista May 14 at 13:03
• There is no unique answer to this question. A mixture water-ethanol may boil at a temperature between $78$°C and $100$°C, depending on the relative proportion of the constituants. A mixture of two non miscible liquids like oil + water boil at a given temperature, whatever the proportions of the constituants. – Maurice May 14 at 20:37
• It would be nice to know which books you are reading. – Martin - マーチン May 15 at 9:03