## Calculation of the degree of Association

Calculation of the degree of Association : The fraction of the total number of solute molecules which exist in the form of associated molecule is called degree of association.

## Calculation of the degree of Dissociation

Calculation of the degree of Dissociation : The fraction of the total number of electrolyte molecules that undergoes dissociation is called degree of dissociation.

## Abnormal molecular mass and Van’t Hoff factor

Abnormal molecular mass and Van’t Hoff factor : When the molecular mass of a substance determined by studying any of the colligative properties comes out to be different than the theoretically expected value.

## Osmotic Pressure

Osmotic pressure : It can be defined as the additional pressure applied on the solution to prevent the entry of the solvent into the solution through semi-permeable membrane. It is represented by ‘π’.

## Depression in freezing point

Depression in freezing point : Freezing point of a substance is the temperature at which the solid and liquid forms of the substance have same vapour pressure.

## Elevation in boiling point

Elevation in boiling point : The boiling point of liquid is the temperature at which the vapour pressure of the liquid becomes equal to the atmospheric pressure.

## Relative lowering of vapour pressure

Relative lowering of vapour pressure : The vapour pressure of solvent in solution is less than that of pure solvent. This is because of non-volatile solute occupy some surface area; hence the vapour pressure decrease.

## Colligative Properties

Colligative Properties are those properties of ideal solutions which depend only on the number of solute particles but do not depend on the nature of solute are called colligative properties.

## Azeotropes

Azeotropes are the binary solution having the same composition in both liquid and vapour phase, and boil at a constant temperature

## Ideal and Non-ideal solutions

Ideal and Non-ideal solutions : An ideal solution may be defined as the solution which obeys Raoult’s law under all conditions of temperatures and concentrations.

## Raoult’s law for solutions containing non-volatile solute (Vapour pressure of solid-liquid solution)

Raoult’s law for solutions containing non-volatile solute (Vapour pressure of solid-liquid solution) : When the solute is non-volatile, only the solvent molecules are present in the vapour phase. Therefore, the vapour pressure of solution is due to solvent only.

## Raoult’s law for solutions containing volatile solute (Vapour pressure of liquid-liquid solution)

Raoult’s law for solutions containing volatile solute (Vapour pressure of liquid-liquid solution) : When a binary solution of two volatile liquids is placed in a closed vessel, both components would evaporate and eventually an equilibrium would be established between liquid and vapour phase.

## Vapor pressure and factors affecting it

Vapor pressure and factors affecting it : The pressure exerted by the vapours above the liquid surface at the time of equilibrium at a given temperature is called vapour pressure.

## Solid solutions (Alloys)

Solid solutions (Alloys) are those solutions in which both solute and solvent are solids.

## Henry’s law and its applications

Henry’s law and its applications : Henry’s law may be defined as :
The pressure of a gas over a solution in which the gas is dissolved is directly proportional to the mole fraction of the gas dissolved in the solution.

## Factors affecting solubility of gases in liquid

Factors affecting solubility of gases in liquid : Typically, those gases that are easily liquefied (or have high critical temperatures) are more soluble in the solvent.

## Factors affecting solubility of Solids in liquid

Factors affecting solubility of Solids in liquid : Every solid does not dissolve in a given liquid. In general, a solid dissolve in a liquid (solvent) if the intermolecular interactions are similar in solute and solvent. This is expressed by saying “Like dissolves like”.

## Normality

Normality of a solution : It may be defined as the number of gram equivalents of the solute dissolved in 1 litre of the solution. It is denoted by ‘N’.