Which of the following exhibits the strongest hydrogen bond?

The crystal lattice of ice is mostly formed by

Which of the following compounds shows evidence of the strongest hydrogen bonding?

Which of the following halogen acids is a liquid?

Structures of molecules of two compounds are given below:
$(a)$ Which of the two compounds will have intermolecular hydrogen bonding and which compound is expected to show intramolecular hydrogen bonding.
$(b)$ The melting point of a compound depends on,among other things,the extent of hydrogen bonding. On this basis,explain which of the above two compounds will show a higher melting point.
$(c)$ Solubility of compounds in water depends on the power to form hydrogen bonds with water. Which of the above compounds will form hydrogen bonds with water easily and be more soluble in it?

Which one of the following compounds shows the presence of intramolecular hydrogen bond?