Question

How do gases differ from liquids?

Short answer

Gases and liquids are fluids, but they differ in different characteristics such as volume, intermolecular spacing, compressibility, density, etc.

Step-by-step solution

Identifying the difference in volume and arrangement of particles

Both liquids and gases do not have a fixed shape. But in the case of volume, liquids possess a definite volume while gases do not. The arrangement of particles is different in gases and liquids. Molecules are very loosely packed in gases in comparison with liquids.

Identifying the difference in compressibility

Since the intermolecular space is larger in gases, particles can easily diffuse compared to liquids. The intermolecular force of attraction is less in gases than in liquids. This makes gases easily compressible. But a great effort is required to compress a liquid.

When placed in an open container, the gases will escape from the container. While a liquid is placed in the same, none of the molecules escape from the container.

Identifying the difference in density

A gas has a lower density than a liquid. Density is the ratio of mass to volume. Since the molecules are loosely packed in a gas, they will occupy more space. So, the increased volume of gases leads to a decrease in gas density compared to liquids.

Thus, unlike liquids, gases do not have a definite volume and are highly compressible and less dense.