At standard pressure, #CH_4# boils at 112 K and #H_2O# boils at 373 K. What accounts for the higher boiling point of #H_2O# at standard pressure?

1 Answer
Dec 31, 2016

Intermolecular force differentiates..........

Explanation:

Between water molecules, hydrogen bonding operates, which is a potent intermolecular force. The #H-O# bond is quite polar, i.e. #""^(delta+)H-O^(delta-)-H^(delta+)#, and the dipoles can align. No such intermolecular force operates between methane molecules, (because the #C-H# bond is reasonably non-polar), and the boiling point of methane is substantially reduced with respect to water.