A solution containing 4 g of a non-volatile organic solute per 100 mL was found to have an osmotic pressure equal to 500 cm of mercury at 27oC27oC.The molecular weight of solute is:

  • A 14.97

  • B 149.7

  • C 1697

  • D 1.497

Asked by gangaram0 | 15th Jul, 2018, 02:21: PM

Expert Answer:

 
 
 
 
 
Option (B) is correct.
 
Given:
 
Weight of solute , W = 4 gm
 
Volume, V= 100 ml
 
            V = 0.1 litre
 
Osmotic pressure, Π = 500 cm of Hg
 
                           Π = 6.57 atm
 
Tmpearture, T = 27 °C 
 
                   T = 300 K
 
We know,
 
πV space equals nRT

6.57 cross times 0.1 equals straight W over straight M cross times 0.082 cross times 300

straight M equals space molecular space weight

straight M equals fraction numerator 4 cross times 0.082 cross times 300 over denominator 6.57 cross times 0.1 end fraction

straight M equals 149.7
 
 
The molecular weight of solute is 149.7

Answered by Varsha | 15th Jul, 2018, 06:36: PM