Question

Liquid ice is denser than ice due to:
A) Higher surface tension
B) Hydrogen bonding
C) Van der Waals forces
D) Covalent bonding

Answer 1

We know that is a physical property of matter. Density expresses the relationship between the mass and the volume of matter. If two substances have equal volumes, then the substance with more mass is more dense.

Complete step-by-step answer:
Density is defined as the ratio of mass of the object to the volume of the object. Different substances have different densities.

The mathematical expression for density is as follows:
${\text{Density}} = \dfrac{{{\text{Mass}}}}{{{\text{Volume}}}}$
The mass of a substance is expressed in kilograms and the volume is expressed in litre. Thus, the unit of density is ${\text{kg }}{{\text{L}}^{ - 1}}$.

The property of a system which is independent of the amount of matter present in the system is known as an intensive property. The density of a substance does not depend on the amount of the matter. The density of one kilogram and two kilogram of water is the same. Thus, density is an intensive property.
Ice forms a hexagonal three dimensional crystal lattice due to intermolecular hydrogen bonding. In the hexagonal three dimensional crystal lattice, half of the space remains unoccupied.

When ice melts, some hydrogen bonds break and the empty space gets occupied by water molecules. Thus, the mass of liquid ice increases. Thus, liquid ice is denser than ice. This liquid ice is denser than ice due to hydrogen bonding.

Thus, the correct option is (B) hydrogen bonding.

Note: The density of substance varies with temperature and pressure. When we apply pressure to an object, its volume decreases and thus, density increases. When we increase the temperature of an object, its volume increases and thus, density decreases.