Solutions

Homogeneous mixture

Homogeneous mixture

Components and properties are Uniform throughout the mixture

Solvent

The component that is present in the largest quantity is known as solvent. Solvent determines the physical state in which the solution exists

Solute

Other components present in the solution except solvent are called solute.

Mass percentage

(Mass of the component in the solution/Total mass of the solution)*100

Volume percentage

(Volume of the component/total volume of the solution)*100

Mass by volume percentage

Mass of the solute dissolved in 100 ML of solution

Parts per million

(Number of parts of the component/total number of parts of all components of the solution)*100

Mole fraction

(Number of moles of the Component/Total number of moles of all the component)

Molarity

Moles Of solute/Volume of solution in litre

Molality

moles of solute/Mass of solvent in kilogram

Solubility

Solubility of a substance is its maximum amount that can be dissolved in a specified amount of solvent at a specified temperature. It depends upon the nature of solute and solvent as well as temperature and pressure.

Dissolution

when a solid solute is added to the solvent, some solute dissolves and its concentration increases in solution. This process is known as dissolution.

crystallisation

Some solute particles in solution collide with the solid solute particles and get separated out of the solution. This process is known as crystallisation.

Effects of temperature on solubility of a solid in liquid

In general, if in a nearly saturated solution, the dissolution process is endothermic, the solubility should increase with rise in temperature and if it is exothermic, the solubility should decrease.

Effect of pressure on solubility of a solid in a liquid

pressure does not have any significant effect on solubility of solid in liquid because solids and liquids are highly incompressible and practically, remain unaffected by changes in pressure

How does pressure affect the solubility of gas in a liquid?

increase in pressure will increase the number of gaseous particles per unit volume over the solution and also the rate at which the gas particles are striking the surface of solution to enter it thus the solubility of liquid increases.

Henry’s Law

The law states that at constant temperature, the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas present above the surface of the liquid or solution.

Henry’s law

The partial pressure of the gas in vapour phase is proportional to the mole fraction of the gas in solution

P=KH X Where KH is Henry law’s constant

Effect of temperature on solubility of a gas in a liquid

Solubility of gases in liquid decrease with rising temperature

Raoult’s law

For a solution of volatile liquids, the partial vapour pressure of each component of the solution is directly proportional to its mole fraction present in solution

Dalton’s law of partial pressure

The total pressure over the solution phase in the container will be the sum of the partial pressures of the components of the solution

Why is Raoult’s law a special case of Henry’s law?

If we compare the equations for Raoult’s law and Henry’s law, it can be seen that the partial pressure of the volatile component or gas is directly proportional to its mole fraction in solution . Only the proportionality constant KH differs from P.

Vapour pressure

Liquids at a given temperature vaporise and under equilibrium condition the pressure exerted by the vapours of the liquid over the liquid phase is called vapour pressure.

Colligative Properties depend on

Number of solute particles irrespective of their nature relative to the total number of particles present in the solution