Propane is Nonpolar

Since carbon and hydrogen have similar electronegativities (2.5 for C and 2.2 for H) the C-H bonds in propane are almost absolutely covalent (EN difference = 0.3).

One would call them “nonpolar”.

Of course, the C-C bonds are absolutely covalent (and also, of course, nonpolar).

In fact, propane is a totally nonpolar molecule – it has no dipoles.

You might think this makes propane on the boring side… but this assessment is totally negated with the addition of oxygen and a flame (see delicious steak in another post). But more on that later. Suffice it to say for now that no polarity surprises will explode in your face if you go with propane!

Without dipoles, the only intermolecular forces possible in propane are dispersion forces, which come from the creation of temporary (induced) dipoles in these molecules. These weak intermolecular forces make propane molecules not all that attracted to each other, leading to a low boiling point of -42.1 degrees C.

Propane’s freezing point is much lower, at -187.7 degrees C. Now that’s COLD.