Real Gases

A gas which obeys the ideal gas equation, PV =nRT under all conditions of temperature and pressure is called an ideal gas. There is no gas which obeys the ideal gas equation under all conditions of temperature and pressure. The gases are found to obey the gas laws if the pressure is low or the…

Viscosity

Some liquids like water, ether flow rapidly why some other liquids like glycerine ,castor oil flow quite slowly. This internal resistance to flow possessed by a liquid is called its viscosity The liquids which flow slowly ,have high internal resistance which is due to strong intermolecular forces and therefore, are said to be more viscous…

Surface Tension

Surface tension is a property of liquid which arises due to the fact that the molecules of the liquid at the surface are in different situation than those in the interior of the liquid. A molecule lying inside the liquid is surrounded by other molecules and so is attracted equally in all directions. Hence ,the…

Vapour Pressure

In a liquid, the molecules are quite close together so that there are considerable forces of attraction between them and hence they are held together in a definite volume. The liquids possess fluidity like gases but incompressibility like solid. Properties of liquid 1)Liquids have no definite shape: They take up the shape of the vessel…

Deduction of Gas Laws From kinetic Theory

Boyle’s law At constant temperature, the average kinetic energy and hence the average speed of the molecules is constant.The number of molecules present in a given mass of a gas is also constant. Let the volume of a given mass of a gas be reduced to one half of its original volume. The same number…

Maxwell-Boltzmann Distribution

Maxwell-Boltzmann distribution of Molecular speed At a particular temperatures, different molecules of a gas possess different speeds. Due to continues collision among the molecules themselves and against the walls of the container ,their speed keep on changing. As a result of collision, some others are speeded up, some others are slowed down and hence the…

Liquefaction Of Gases And Critical Temperature

The liquefaction of a gas takes place when the intermolecular forces of attraction become so high that they bind the gas molecules together to form the liquid state. The intermolecular forces of attraction can be increased either by increasing the pressure so that the molecules come close together or by cooling the gas so that…

Kinetic Molecular Theory Of Gas

Kinetic theory of gases Postulates or assumptions of kinetic theory of gases 1)Every gas is made up of a large number of extremely small particles called molecules. All the molecules of a particular gas are identical in mass and size and differ in these from gas to gas. 2)The molecules of a gas are separated…

Gas Laws

Boyle’s law The relationship between the volume and pressure of a gas was studied experimentally by Robert Boyle in 1662. He used mercury and a simple  U-tube.The pressure was increased by putting more mercury into the open limb. The volume of the air enclosed in the space above mercury in the shorter limb was noted…

Characteristics Of Gases

Characteristics of gases 1)Gases have neither definite shape nor definite volume. They take up the shape and volume of the container. 2)They have lower density than liquids and solids.   3)They are highly compressible 4)Gases intermix completely in all proportion without any mechanical aid. 5)They exert pressure equally in all direction. Measurement of mass The…

Intermolecular forces

A given substance can be made to exist in any one of the three states under different conditions of temperature and pressure. Water which is a liquid under ordinary conditions of temperature and pressure can be converted into steam at 100°C and under 1 atmosphere or into ice by cooling at 0°C  under 1 atmosphere…