Forces between molecules - dipole-dipole

Question 1

between what type of molecules do dipole-dipole forces occur?

Answer 1

polar molecules

Question 2

how do dipole-dipole forces work?

Answer 2

the positive part of each molecule is attracted to the negative part of neighbouring molecules - this is a dipole-dipole interaction

Question 3

how do the strength and boiling point of dipole-dipole forces compare to van der Waals’ forces?

Answer 3

much stronger
higher melting and boiling point

Question 4

why are dipole-dipole interactions stronger and have higher BPs than vdW?

Answer 4

dipoles are always present in polar molecules, compare constantly forming and reforming dipoles causing van der Waals’ forces