Question

the osmotic pressure of decimolar solution of urea at 27degree C

1) 2.49 bar

2) 5bar

3) 3.4 bar

4) 1.25 bar

Answer 1

Use the formula π = cRT
​Decimolar solution means concentration of solution is 1/10 M or 0.1 M solution.
V = 1 L
c = 0.1 mol
T = 27° C = 273 K + 27 = 300 K
​R = 0.0821 L atm K-1 mol-1
π = cRT / V
= 0.1 mol x 0.0821 L atm K-1 mol-1 x 300K / 1 L
​ = 2.463 atm
​
Now, 1 atm = 1.01325 bar
So, 2.463 atm = 2.463 x 1.01325 bar = 2.49 bar