Liquid and Gas – Characteristics and Comparison

Liquid and Gas

This is about Liquid and Gas Characteristics, Comparison between both fluids.

Liquid is a fluid which of its container. Other words, liquid possess definite mass and volume without definite shape.

A given liquid mass occupies a fixed volume, irrespective of size & shape of container.
Since assumption of liquid to be in-compressible, it will form a free surface if the container volume is greater than liquid as shown in figure.
In liquids, the spacing between molecules is relatively higher as compared to solids, that means that inter-molecular cohesive forces are smaller in liquids. This allows liquid molecules to move freely within liquid mass.
For liquids at narrow pressure above zero, depends on temperature.

Gas is a fluid which is definite mass but no definite volume and shape.

A gas is relatively easily compressed and it is regarded as a compressible fluid.
A mass of gas given has no fixed volume and It will expanding continuously unless restrained by a containing vessel.
The spacing between molecules is extremely larger when compared to solids and liquids, that means inter-molecular cohesive forces is smaller in gases. So molecules of gas having greater free of moment. They will container completely in which they are placed.
The volume of gas is depends on pressure and temperature. For instance, If the gas volume decreases then temperature and pressure of it increases.

Comparison between liquid and gas
SI.NO	Liquid	Gas
1	Possess a definite volume for a given mass of liquid, but conforms to shape of container.	It having a definite mass, but it does not posses a definite volume and conforms to shape of the container.
2	Since it posses a definite volume, it forms a free surface if the volume of container is greater than volume of liquid filled.	Since it does not have possess the definite volume, it will be expands and occupies the whole volume of container.
3	Fluid is incompressible	Fluid is compressible
4	The spacing between molecules is extremely larger when it compared to solids, but it relatively very less when it compared to gas.	The spacing between molecules is relatively larger when it compared to solids and liquids.
5	It can be contain in open vessel	It always needed to contain in a closed vessel.