CHEMISTRY   
       
  SOLUTION:

A solution is a homogeneous mixture of two or more substances. It comprises of two components namely SOLUTE and SOLVENT. The solution may exist in any form, solid, liquid or gas but it is always in the form of the solvent.

The differences between a solute and solvent are:
 
 
BASIS SOLUTE SOLVENT
STATE OF MATTER OF SOLUTION The solution may not be in the state of matter of the solute The solution is in the same state of matter as the solution 
PROPORTION OF PRESENCE The proportion of presence in the solution is less The proportion of presence in solution is more
FUNCTION Tends to disperse in the solution Acts as a medium of dispersal for the solute
 
 
Types of solutions:
  
    • Aqueous
  • Non- aqueous
  • Concentrated
  • Dilute
  • Saturated
  • Unsaturated
  
  Aqueous and non-aqueous solutions  
 
Aqueous solutions are those which contain water as the solvent. E.g. salt solution (salt in water) Non-aqueous solutions are those which contain a solvent other than water. E.g. naphthalene in benzene.
  
  Concentrated and dilute solutions  
 
A solution containing comparatively more solute is known as a concentrated solution.

A solution containing comparatively less solute is known as a dilute solution.
  
  Saturated and unsaturated solutions  
 
A solution which does not have the capacity to dissolve any more solute at a particular temperature is known as a saturated solution.
A solution in which no more solute can be dissolved is known as an unsaturated solution.
  
  Solubility:  
 
Solubility can be defined as the maximum amount of solute that can be dissolved in 100gm of a solvent at given temperature and pressure. 		 
  OR  
 

Solubility =                   Weight of the solute in a saturated solution x 100  

                                   Weight of the solvent in a saturated solution

  
 
FACTORS AFFECTING THE SOLUBILITY OF A SOLID SOLUTE IN WATER:		  
 
• Temperature- an increase in the temperature increases the solubility of the solute.
• Size- larger the size of the solute particles, greater the solubility.
• Mechanical stirring- mechanical stirring increases the solubility of the solute.
  
 
FACTORS AFFECTING THE SOLUBILITY OF A GASEOUS SOLUTE IN WATER:		  
 
• Temperature- an increase in the temperature decreases the solubility of a gaseous solute.
• Pressure- an increase in the temperature increases the solubility of a gaseous solute.		  
 
DIFFERENCE BETWEEN TRUE SOLUTIONS, SUSPENSION AND COLLOID:
  
 
BASIS TRUE SOLUTIONS SUSPENSION COLLOID
TYPE OF MIXTURE Homogeneous or heterogeneous Heterogeneous Particles easily visible Homogeneous
SIZE OF PARTICLES Very small Larger Smaller
SEDIMENTATION No sedimentation Particles settle down to form layers Particles do not settle down
VISIBILITY Particles not visible even under a microscope Particles easily visible Residue is formed Particles visible only under a microscope
EFFECT OF FILTRATION No residue formed Residue is formed No residue is formed