[kylefoley76]

In this book I see a picture of CH3 surrounded by water molecules.  I don't see why the hydrogen on the CH3 forms a hydrogen bond with the water molecules

[saden99]

Isn't this just normal hydrogen-hydrogen bonding?

I might be confused by what your asking. CH3 doesn't exist on its own. What point is the book trying to make (under what topic/chapter is this?)

[kylefoley76]

no, this is not hydrogen bonding, if it was hydrogen bonding then it would be hydrophilic.  woops, i made a mistake.  it's hydrophobic in my above example.  i need to know why it's hydrophobic.

[saden99]

O'...that's easy.

Polarity.

C-H bonds (hydrocarbons really) are typically non-polar.

Are you sure it's forming a bond in the textbook, or is the textbook trying to say there is some sort of attraction? Taking oil as an example, when you put oil in water and shake it around there is a "mixture", but the solution eventually separates. It has to do with the "spread" of the attraction to the water compared to a molecule of oils' attraction to another molecule of the same oil.

I hope that made sense...

Just remember that 'like dissolves like' so polar dissolves in polar and non-polar in non-polar...but not non-polar in polar. And water is always polar.