Thursday, March 27, 2014

Solution and different aspect of solution.

Definition:
Solution is a homogeneous mixture of two or more substances (solid, liquid or gases) uniformly distributed among each other.

Homogeneous mixture (homogeneous system)
It is the mixture of two or more substances showing all through same composition.

Heterogeneous mixture (heterogeneous system)
It is the mixture of two or more substances showing different composition in different parts of the total mixture.

Phase:
It is the homogeneous part or parts of a system separated from each other by definite separating surfaces' In homogeneous mixture there is only orru pilur", but in heterogeneous mixture there is more than one phase.
eg: Solid ice floating in water is a system constituted by the mixture of ice and water; here
solid ice represent one phase and water represent another phase.

Solvent:
  • Solvent is the component of a solution which forms larger portion of that solution. 
  • Physical state of the sorvent must be same as that of solution.
Solute: 
  • Solute is the component(s) of a solution which form minor portion of that solution.
  • Solutes are held in solution by the solvent.
eg: 0'9% NaCl solution: Here water is solvent because it represents the major portion and its physical state (liquid) is like that (liquid) of solution. Here sodium chloride is solute
because NaCl represent minor portion of solution and it is kept in solution by water.
5%DA (dextrose in aqua): Here dextrose is solute and water is solvent.
 
Heterogeneous solution
It is a heterogeneous mixture of two or more substances constituting a multi phase system having different composition in different parts of the system, e.g. solution of protein in water.
 
Homogeneous solution or true sorution (molecular sorution) 
  • It is a homogeneous (singre phase) mixture of sorute and sorvent.
  • Solutes exist in the form of molecules/ ions in this solution.
  • Here solutes are crystalloid with size less than 1 nm.
  • Here solutes do not sediment out even on indefinite standing.
  • The difference between solute and solvent molecules with respect to their size is relatively small.
  • Solutes cannot be separated from solvent by passing it through filter paper or semipermeable membrane.

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