1 l of aqueous solution of sucrose molar mass 342 gram per mole having wait 10 15 gram is found to record an Osmotic pressure of 4.82 ATM at 293 Kelvin what is the molality of the solution

Asked by Singh.sonali5775 | 13th Jul, 2018, 07:13: PM

Expert Answer:

Given:
V = 1 litre
 
Weight of solution = 1015 g
 
Molar mass of solute = 342 g
 
T = 293 K
 
Osmotic pressure, Π = 4.82 atm
 
R =0.0821 ltratm/Kmol
 
We know,
πV equals space nRT

πV space equals straight w over straight M RT

straight w space equals πVM over RT

space space space space equals fraction numerator 4.82 cross times 1 cross times 342 over denominator 0.082 cross times 293 end fraction

straight w space equals 68.6 space straight g

Weight space of space solvent space equals space 1015 minus 68.6

space space space space space space space space space space space space space space space space space space space space space space space space space space space equals 946.6 space straight g
space space space space space space space space space space space space space space space space space space space space space space space space space space
space space space space space space space space space space space space space space space space space space space space space space space space space space space equals 0.946 space kg

Molality equals fraction numerator No. space of space moles space over denominator Weight space of space solvent space in space kg end fraction

space space space space space space space space space space equals space fraction numerator begin display style bevelled fraction numerator 68.6 over denominator 342 end fraction end style over denominator 0.946 end fraction

space space space space space space space space space equals space 0.21 space straight m
 
Molality of solution is 0.21 m

Answered by Varsha | 14th Jul, 2018, 01:17: PM