The number of $H_2O$ molecules participating in hydrogen bonding in $CuSO_4 \cdot 5H_2O$ is/are

When two ice cubes are pressed over each other,they unite to form one cube. Which of the following forces is responsible for holding them together?

$Statement-1$: $p$-Hydroxybenzoic acid has a lower boiling point than $o$-hydroxybenzoic acid.
$Statement-2$: $o$-Hydroxybenzoic acid has intramolecular hydrogen bonding.

Which concept best explains that $o-$nitrophenol is more volatile than $p-$nitrophenol?

Hydrogen bonding is present in

Hydrogen bonding is maximum in