[Paulo1913]

Hello.
I have been having trouble figuring out how to answer this question...

The boiling points of three compounds are: CH₃OH, 65C;   CH₃Cl, –24C;   CH₃Br, 4C

Discuss the relative strengths of the intermolecular forces in liquid samples of these three compounds.

[AWK]

You have all needed data for a such disscussion.

[Paulo1913]

This is what I put:

CH3OH
• Strongest intermolecular forces.
• Only molecules which can hydrogen bond (to each other).
• H bonds possible because (very electronegative) O bonded
to H causing large σ+ on H (which is attracted to lone pair
e–s on O of neighbouring atoms).
CH3Br and CH3Cl
• Cl is more electronegative than Br so CH3Cl is more polar
than CH3Br so permanent dipoles are stronger.
• CH3Br molecule is larger than CH3Cl so has more e–s so
more polarisable, and temporary dipole attractions between
molecules will be stronger.
• CH3Br has stronger overall forces of attraction between its
molecules than CH3Cl (since boiling point is higher), so
temporary dipoles have greater influence on boiling point
than permanent dipoles.

[lancenti]

That sounds right but you may want to write "BUT" between the 1st and 2nd points for CH₃Cl VS CH₃Br just to make your answer clearer.