Question

define osmotic pressure why does osmotic pressure become abnormal​

Answer 1

Answer :

Osmotic Pressure:-

The extra pressure that must be applied to the soln component to prevent the flow of solvent into the solution when the two are separated by SPM. It is devoted by II. Osmotic pressure be come abnormal due to- (i) Association or dissociation of solute molecule in the soln.

Answer 2

Solution

⇒ The net movement of solvent Molecules from solvent to solution can be stopped by applying some extra pressure over solution side is called Osmotic pressure (π)

" The extra pressure over solution side which stop osmosis"

⇒ π ∝ M ( Molarity of solution )

⇒ M = ( no of moles of solute )/( volume of solution )

⇒ π ∝ T

⇒ π = MRT

Where

⇒ π = Osmotic Pressure

⇒ M = Molarity

⇒ R = Solution Constant

⇒ T =  Absolute Temperature

Osmotic Pressure Become abnormal because

i) Solute become electrolyte

ii) Solute is Volatile

iii) Association or dissociation of molecule

Let Take one example question which essay to understand

⇒ Calculate the Osmotic Pressure Due to 5% (w/v) Cane Sugar Solution at 15° C

Solution

⇒ Formula

⇒ π = MRT ⇒ $\sf \pi =\dfrac{n}{v( in\: L)} \times R \times T$

5 % ( w/v) + 5g cane sugar in 100 ml Solution  and T = 273 + 15 + 288

$\implies \sf \dfrac{\dfrac{5}{342} }{\dfrac{100}{1000} } \times 0.0821\times 288\approx 3.4 atm$