Which of the following compounds exhibits dipole-dipole forces as its strongest attraction between molecules?
a) $\ce{CO2}$
b) $\ce{CH3NH2}$
c) $\ce{Kr}$
d) $\ce{H2}$
e) $\ce{HBr}$
From what I understand, $\ce{CH3NH2}$ has an H-bond and it's the strongest form of dipole-dipole. So I thought that would be the answer.
I also knew that $\ce{HBr}$ shows the greatest electronegativity difference between $\ce{H}$ and $\ce{Br}$ atom, it would be a polar covalent bond (?!).
In that case, $\ce{HBr}$ may have stronger attraction between molecules than $\ce{CH3NH2},$ but it is not dipole-dipole. Isn't that correct? Then shouldn't the answer be $\ce{CH3NH2}$ instead of $\ce{HBr}?$
I must have some concept issues here.