States of matter (Gases and Liquid)

States of matter

Matter: - Everything is matter which occupy space and have a mass.

Q1)  Describe the different states of matter.

The three state of matter

Matter exists in three states Solid, liquid and gases.

In solids the constituent particles are held very closed to each other in some definite orderly manner. Hence all solid have some definite shape. The solid may be amorphous or crystalline. As the particles in solids state are closely packed, they do have freedom for moment. Given mass of all pure solids have definite size, shapes, volume and density. Solids are non-compressible.

When Solids are heated it melt and solid state is transfer into liquid state. In liquid state the constituent molecules are in contact with one another however they are not held firmly as in case of solid state. Hence molecules of liquid have freedom to move from one place to another place. Liquid have definite volume but do not have definite shape. It assume that the shape of the container in which they are stored. Liquids are slightly compressible.

When liquid is heated it boil and transfer into gaseous state. In gases the molecules of gas separated from each other by a large distance as compared with the size of gas molecules. They do not exert any force of attraction on the neighboring molecules. The gas molecules possess kinetic energy depend on temperature and execute continuous random motion. During the motion they collide with each other and also on the wall of the container and exert pressure. Gases do not have definite size, shape and volume. They occupy entire volume of the container. Gases are compressible and also can be expanded.

Q2)  what is intermolecular interaction? What is its roll in sate of matter?

The force of attraction between any two molecules of a substance is called intermolecular force of attraction.

Intermolecular interactions in the form of intermolecular force of attraction are responsible for three state of matter. These forces are maximum in solid and minimum in gaseous state. The forces are intermediate in liquid state. There are three main types of intermolecular interactions. 1) Dipole – dipole interaction 2) Dipole – included dipole interaction, ion included dipole interaction 3) Dispersion forces or London forces.

          Hydrogen bonding is an additional type of intermolecular interaction in which hydrogen atom connected to electronegative atoms like O, N, F or Cl by covalent bond acquires additional positive charges and as a result forms additional bond with electronegative atom of other molecules. Hydrogen bonding is present in molecules like , , HF etc. In gases intermolecular forces of attraction are either absent or they are very weak.

The Gaseous State

We are living on the soil and totally drowned in the surrounding atmosphere. The atmosphere contains oxygen without which life on the earth is impossible. The air present in the atmosphere protect us from cosmic and ultra violet radiations. The atmosphere contain mainly mixture of gases like Nitrogen, Oxygen, Carbon dioxide and water vapour. The moment of air is responsible for movement of clouds which brings rain in the monsoon. Hence the gaseous state has important role in the wellbeing of human beings. Hence the study of gaseous state is essential.