Chemistry · Chapter 20

Alcohols and Ethers

Pick a family and a chain length. Count how many hydrogen bonds the molecule can make, then check that count against the measured boiling point and the measured solubility in water.

The molecule gold dashes are hydrogen bonds

The molecule and the water around it

An alkane has nothing polar to offer, so water molecules stay with each other instead.

Boiling points across the set your pick is in teal

Measured boiling points

Measured values

methane no O–H
Formula
CH4
Molar mass (g/mol)
16.04
Boiling point
−161.5 °C
Solubility in water
almost none
H bonds it can give
0
H bonds it can take
0

Choose

Family

Guess first

How the group drives it
Set a molecule and make a guess
An O–H bond lets a molecule grab the next one. That grip has to be broken before the liquid can boil, so each OH group pushes the boiling point up hard.