# Homework Help: Hydrogen bond between tetrafluoromethane and water

1. May 29, 2013

### davon806

1. The problem statement, all variables and given/known data
My textbook wrote that haloalkanes are generally insoluble in water.It is because the polar
C-X bonds are not polar enough to make the haloalkanes soluble in water.

Consider tetrafluoromethane
Difference in electronegativity between F and C = 4.0 - 2.5 = 1.5
Difference in electronegativity between O and H = 3.5 - 2.1 = 1.4
Difference in electronegativity between F and H = 4.0 - 2.1 = 1.9

So C-F bond is more polar than O-H bond in water,and much more polar than F-H bond
Therefore hydrogen bonds should form between a F atom in tetrafluoromethane and a H atom in a water molecule.

However,according to the data provided in wikipedia,tetrafluoromethane is nearly insoluble in water at r.t.p.,can anyone explain?

Thx

2. Relevant equations

3. The attempt at a solution

2. May 31, 2013

### AGNuke

Hydrogen Bond is a special case of a dipole-dipole attraction. It works between polar molecules. The group participating in H-Bonding must hence be polar. And obviously Tetrafluoromethane is non-polar.