the relationship between osmotic pressurev at 273 K when 10 g glucose (P1),10g urea(P2) and 10 sucrose(P3) are dissolved in 250 ml of water:

(A)P1>P2>P3 (B)P3>P2>P1(C) P2>P1>P3(D)P2>P3>P1;EXPLAIN IT

Dear bharat,

The osmatic pressure is given by

Π = iMRT,

where

i is the dimensionless van 't Hoff factor

M is the molarity

R=0.08206 L · atm · mol^-1 · K^-1 is the gas constant

T is the thermodynamic (absolute) temperature

the osmatic pressure is directly proportional to the Molarity,since other values are constant for the three compounds.

The molarity is inversly proportional to Molecular weight.

Molecular weight of

Urea = 60

Glucose = 180

sucrose = 342

Hence our answer is

(C) P2>P1>P3

Please feel free to ask your queries here. We are all IITians and here to help you in your IIT JEE preparation.

All the best.

Win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian.

Now you score 5+15 POINTS by uploading your Pic and Downloading the Askiitians Toolbar  respectively : Click here to download the toolbar..

 

Askiitians Expert

Suryakanth –IITB

  P=CRT

osmotic pressure is inversly proportional to molar mass if all other parameteres are constant so higher will be the molar mass lower will be the osmotic pressure

 hence option c is correct

Dear Student,
Please find below the solution to your problem.

The osmatic pressure is given by
Π = iMRT,
where
i is the dimensionless van 't Hoff factor
M is the molarity
R=0.08206 L · atm · mol-1 · K-1 is the gas constant
T is the thermodynamic (absolute) temperature
The osmatic pressure is directly proportional to the Molarity,since other values are constant for the three compounds.
The molarity is inversly proportional to Molecular weight.
Molecular weight of
Urea = 60
Glucose = 180
sucrose = 342
Hence our answer is
(C) P2>P1>P3

Thanks and Regards