Osmosis | osmotic pressure | types of solution on the basis of osmotic pressure | isotonic solution | hypotonic solution | hypertonic solution | reverse osmosis |

Osmosis : 

✓ Spontaneous uni-directional movement of solvent through semi permeable membrane from lower concentration of solution to higher concentration of solution is known as osmosis.

[ Here Lower concentration of solution means  a Diluted solution ( in which amount of solute is less than the amount of solvent. )

And higher concentration of solution means a concentrated solution ( in which amount of solute is more than amount of solvent .)

Semipermeable membrane (SPM) : 

membrane having a network of submicroscopic holes or pores by which small molecule like solvent can pass through it but larger molecule like salute is hindered is known as semi permeable membrane. ]

Osmotic pressure (π) : 

✓ The extra pressure applied on the side of solution so that the net flow of solvent through the semipermeable membrane is stoped , the extra pressure is known as osmotic pressure.

✓ Osmotic pressure represent as pi (π).

By experiment it is found that osmotic pressure is directly proportional to Molarity of the solution and also temperature. 

So , 

π = RMT 

[  Here  R is solution constant and value of R is 0.082 atm - litter/ mole- Kelvin

M is molarity of the solution

T is temperature in Kelvin ]

✓ On the basis of osmotic pressure solution are of three types --

1. Isotonic solution

2. Hypotonic solution

3. Hypertonic solution

1. Isotonic solution : 

At a given temperature if two solution having same osmotic pressure then the solution is known as isotonic solution.

examples:  0.02 M urea solution age isotonic with 0.02 M glucose solution. 

2. Hypotonic solution :

At a given temperature  If  a solution having lower osmotic pressure than other one solution then the solution is known as hypotonic solution.

examples; 0.04 M urea is hypertonic to 1M (molar) of glucose solution.

3. Hypertonic solution :

At a given temperature if a solution having higher osmotic pressure than the other one solution ,  then the solution is known as hypertonic solution.

examples ; 1M ( one molar ) sucrose  solution is hypertonic with 0.05 molar urea solution.

Reverse osmosis (R.O.) :

✓ Non-spontaneous process in which direction of osmosis is reversed when applied pressure is larger than osmotic pressure , then this type of phenomenon is known as reverse osmosis.

✓ reverse osmosis is used for purification of water.