Name two properties of water that are unusual because of the presence of hydrogen bonding between adjacent water molecules.

The hydrogen bonding is a kind of association, which is present in water. The following are the two unusual properties of water because of the presence of hydrogen bonding between the adjacent water molecules are as follows:  

1. The water molecules are stabilized by these hydrogen bonds, so dissociating the molecules is very tough. The hydrogen bonds hold for the high boiling point of water and the tendency to captivate heat. When water freezes, the hydrogen bonds lock water into an open framework, which comprises a lot of vacant space.  

2. In liquid water, the molecules can get somewhat close to each other, however, when the formation of solids takes place, the hydrogen bonds results in a composition, which comprises bigger holes. The holes reduce the density and elevate the volume. This procedure tells that why the ice density is less in comparison to the liquid water.