Question

What would be the osmotic pressure of the system at 300 k temperature ? (R = 8.314 x 10^-2 litre-bar-mole^-1 k^-1) (Assume that lomic solid substances completely dissociates in an aqueous solution)

(a)  25 bar

(b)  10.0 membrane bar

(c)  24.9 bar

(d)  19.95 bar 

Answer 1

Correct option  (b) 10.0 membrane bar

Explanation:

Whiten x Suppose x m₁ H₂O is transferred from aqueous solution of KCI to aqueous solution of Alcl₃ then the phenomenon osmosis stops. So morality of soluble particles in both solutions becomes equal at this time.

M₁  = modality of kcl solution

M₂  = modality of kcl solution when x ml water is reduced. M₁ V₁ = M₂ V₂

0.2 x 2000 = M₂ x (2000 x)

:.  M₂ =  400/2000 X

Similarly volume of Alcl₃ Solution increases by addition of x m₁ H₂O.

morality of Alcl₃ solution = 600/2000 + X

Now morality soluble particles in kcl solution = morality of soluble particles in Alcl₃ soln.