Why do boiling points differ between materials?

1 Answer
Jan 8, 2018

Answer:

Because different liquids have different degrees of intermolecular force?

Explanation:

Let us take 2 common liquids: #"(i) water; and (ii) diethyl ether...."#

At #34.6# #""^@C#, water has a vapour pressure of #41.1*mm*Hg#...but at this temperature, diethyl ether has a vapour pressure of #760*mm*Hg#. How did I know the latter? Because I know that at the #"normal boiling point"#, the vapour pressure of the liquid is #1*atm-=760*mm*Hg#. (How did I know the former? Well, I have got a handy table in front of me that tells me the vapour pressure of water at various temperatures.)

So a question for you to consider, what is the vapour pressure of water at #100# #""^@C#?