Question

An aqueous solution contains 0.4 urea and 3.42 %sugar by mass calculate the osmotic pressure of the solution at 27 degree c

Answer 1

Osmotic presuure=i*C*R*T,
where, C=concentration of solute(in terms of Molarity)
R= Gas constant=0.082 L(atm)(mol)-1K-1
T=temperature (in Kelvin)
i=Van’t-Hoff factor(=1 for non-electrolyte)
5% urea solution means 5g urea is present in 100ml of solution.

mole of urea=weight given/Molecular weight of urea
= 5g/60gmol-1=1/12
Hence Concentration(C) of urea (in terms of Molarity)
= (mole of urea(n)/Volume of solution)*1000
={(1/12)/100}*1000
=10/12

Hence Osmotic pressure=1*(10/12)*0.082*272 atm
=18.59 atm