Question
What is Osmosis? What is Osmotic Pressure? Derive it's formula.
✓
Answer
$\rightarrow$ If semi permeable membrane is placed between the solvent and solution as shown fig. the solvent molecules will flow through the membrane from pure solvent to the solution.
This process of flow of the solvent is called osmosis.
$\rightarrow$ The flow will continue till the equilibrium is attained
$\rightarrow$ The flow of the solvent from its side to solution side across a semipermeable membrane can be stopped if some extra pressure is applied on the solution.
This pressure that just stops the flow of solvent is called osmotic pressure of the solution.
$\rightarrow$ The osmotic pressure of a solution is the excess pressure that must be applied to a solution to prevent osmosis,
$\rightarrow$ Osmotic pressure is a colligative property as it depends on the number of solute molecules and not on their identity.
$\rightarrow$ osmotic pressure is proportional to the molarity$, C$ of the solution at a given temperature $T$.
$\pi=\text { CRT }$
Where, $\pi=$ Osmotic pressure
$R =$ gas constant
$ \therefore \pi =\frac{n_2 R T}{V} \ \left(\because C=\frac{n_2}{V}\right)$
$\pi =\frac{W_2 R T}{M_2 V}$
$ W _2= Wt . \text { of Solute }$
$M _2=$ Molar mass of Solute
$V =$ Volume of Solution $(L)$
$T =$ Temperature
This process of flow of the solvent is called osmosis.
$\rightarrow$ The flow will continue till the equilibrium is attained
$\rightarrow$ The flow of the solvent from its side to solution side across a semipermeable membrane can be stopped if some extra pressure is applied on the solution.
This pressure that just stops the flow of solvent is called osmotic pressure of the solution.
$\rightarrow$ The osmotic pressure of a solution is the excess pressure that must be applied to a solution to prevent osmosis,
$\rightarrow$ Osmotic pressure is a colligative property as it depends on the number of solute molecules and not on their identity.
$\rightarrow$ osmotic pressure is proportional to the molarity$, C$ of the solution at a given temperature $T$.
$\pi=\text { CRT }$
Where, $\pi=$ Osmotic pressure
$R =$ gas constant
$ \therefore \pi =\frac{n_2 R T}{V} \ \left(\because C=\frac{n_2}{V}\right)$
$\pi =\frac{W_2 R T}{M_2 V}$
$ W _2= Wt . \text { of Solute }$
$M _2=$ Molar mass of Solute
$V =$ Volume of Solution $(L)$
$T =$ Temperature
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
$MnO$ is basic whereas $Mn_2O_7$ is acidic in nature. Give reason.
→Sucrose decomposes in acid solution into glucose and fructose according to the first order rate law, with $t_{1 / 2}$ = 3.00 hours. What fraction of sample of surcrose after 8 hours?
→Indicate the steps in the preparation of :
(i) $K _2 Cr _2 O _7$ from chromite ore
(ii) $KMnO _4$ from pyrolusite ore.
→(i) $K _2 Cr _2 O _7$ from chromite ore
(ii) $KMnO _4$ from pyrolusite ore.
(a) Define molecularity of the reaction-
(b) Explain the effect of the presence of a catalyst on the rate of reaction.
(c) In a first order reaction at 300 k the initial quantity of the reactant was $1.0 X ^{-2} molL ^{-1}$ which reduced to $0.5 \times 10^{-2} molL ^{-1}$ in 30 minutes Calculate the rate constant of the reaction at 300 k .
→(b) Explain the effect of the presence of a catalyst on the rate of reaction.
(c) In a first order reaction at 300 k the initial quantity of the reactant was $1.0 X ^{-2} molL ^{-1}$ which reduced to $0.5 \times 10^{-2} molL ^{-1}$ in 30 minutes Calculate the rate constant of the reaction at 300 k .
Give examples and suggest reasons for the following features of the transition metal chemistry :
(i) The lowest oxide of transition metal is basic, the highest is amphoteric/acidic.
(ii) A transition metal exhibits highest oxidation state in oxides and fluorides.
(iii) The highest oxidation state is exhibited in oxoanions of a metal.
(i) The lowest oxide of transition metal is basic, the highest is amphoteric/acidic.
(ii) A transition metal exhibits highest oxidation state in oxides and fluorides.
(iii) The highest oxidation state is exhibited in oxoanions of a metal.
Explain Raoult's Law for volatile solute and Volatile solvent and derive formula for total vapour pressure with graph.
Write down reaction of halogens with metals. ### Give Fittig, Wurtz - Fittig and Grignard reaction of haloarene.
Out of pure liquid and azeotrope showing positive deviation, Which one has a higher boiling point?
Illustrate with examples the limitations of Williamson synthesis for the preparation of certain types of ethers.
How would you account for the following :
(i) Of the d4 species Cr2+ is strongly reducing while manganese(III) is strongly oxidising.
(ii) Cobalt(III) is stable in aqueous but in the presence of complexing reagents it is easily oxidised.
(iii) The d1 configuration is very unstable in ions.
(i) Of the d4 species Cr2+ is strongly reducing while manganese(III) is strongly oxidising.
(ii) Cobalt(III) is stable in aqueous but in the presence of complexing reagents it is easily oxidised.
(iii) The d1 configuration is very unstable in ions.