Question

Hydrogen bonding can exist only between polar and polar substances and not between non polar and polar or non polar and non polar substances?

Answer 1

Hydrogen bonding is defined as the bond between two electronegative atom which are connected through H bond. The H bond connects the two electronegative atom. Whenever the tow atoms bonded have different electronegative automatically polarity is induced in the molecule. That is why its always between two polar substances.
H-F------H-O-H