SOLUTION [CLASS-12]

CLASS-12                           SOLUTION

                                                                      CONTENTS

1. SOLUTION, BINARY SOLUTION, SOLVENT & SOLUTE, AQUEOUS & NON- AQUEOUS SOLUTION

2.TYPES OF SOLUTIONS ON THE BASIS OF PHYSICAL STATE OF THE SOLVENT

3.EXPRESSING CONCENTRATIONS OF SOLUTIONS

4.SOLUBILITY

1. SOLUTION :-  A solution is a homogeneous mixture of two or more chemically non- reacting substances whose composition can be varied within certain limits. In a homogeneous mixture , all the particles are of molecular size, i.e., up to nanometre in diameter and the different constituents of the mixture cannot be separated by any of the physical methods like filtration, settling or centrifuging. Every solution is made up of a solvent and one or more solutes.

BINARY SOLUTION :- A solution containing only one solute dissolved in a solvent is called binary solution.

SOLVENT AND SOLUTE :- A solvent is that component of the solution which is present in larger amount by mass than the other component, called as solute.

AQUEOUS AND NON- AQUEOUS SOLUTION :- Solutions in water are called aqueous solutions, and the solutions in which water is not the solvent are called non - aqueous solutions. Benzene , ether, carbon tetrachloride etc., are used as solvents in non aqueous solutions.

2. TYPES OF SOLUTIONS ON THE BASIS OF PHYSICAL STATE OF THE SOLVENT

S.No.	Solute	Solvent	Type of solutions	Examples
1.	Solid	Solid	Solid in solid	Alloys(brass, bronze, 22 carat gold etc.)
2.	Liquid	Solid	Liquid in Solid	Hydrated salts, Amalgam of Hg with Na
3.	Gas	Solid	Gas in Solid	Dissolved gases in minerals or H2in Pd
4.	Solid	Liquid	Solid in liquid	Salts/glucose/sugar/urea solution in water
5.	Liquid	Liquid	Liquid in liquid	Methanol/Ethanol in water
6.	Gas	Liquid	Gas in liquid	Aerated drinks, Oxygen in water
7.	SOlid	Gas	Solid in gas	Iodine vapours in air, Camphor in N2gas
8.	Liquid	Gas	Liquid in gas	Humidity in air, Chloroform in N2gas
9.	Gas	Gas	gas in gas	Air ( N2 gas + O2 gas )

3. EXPRESSING CONCENTRATION OF SOLUTIONS

  A). Percentage :

a). Mass % of a component ( w/w) = [Mass of the component in solution / Total mass of solution]  x 100

b) Volume % of a component v/v) = [Volume of the component in solution / Total volume of solution]  x  100                                                                                                                                                                  

c) Mass/volume %  of a component = [mass of the component in solution/ total volume of solution in ml]  x 100          

 B) STRENGTH :- The amount of the solute in gram present in one litre ( or decimetre cube) of the solution is called strength of the solution.

                   strength of a solution = [ mass of the solute in gram/ volume of the solution in litre]

   C) MOLARITY ( M ) :-   The number of moles of the solute dissolved per litre of solution is called molarity. 

                               Molarity = [ number of moles of solute / volume of the solution in litre]

*  unit - mole / litre

* Molarity is temperature dependent.

* Some common fractions of molarity- 

     1M = Molar ,     M/2 = Semimolar ,     M/10 = Decimolar ,      M/100 = Centimolar ,                      M/1000=Millimolar  

* FORMALITY(F) :- The number of gram formula masses of the solute dissolved per litre of the solution is called formality.                                                                                                                                                 

                  Formality = [ number of gram formula mass of solute / volume of the solution in litre] 

 It is used for ionic compounds.