<u>Answer:</u> The mass of urea needed is 12.89 grams
<u>Explanation:</u>
To calculate the concentration of solute, we use the equation for osmotic pressure, which is:
or,
where,
= osmotic pressure of the solution = 24.3 atm
i = Van't hoff factor = 1 (for non-electrolytes)
= mass of urea = ? g
= molar mass of urea = 60.1 g/mol
= Volume of solution = 216 mL
R = Gas constant =
T = temperature of the solution = 298 K
Putting values in above equation, we get:
Hence, the mass of urea needed is 12.89 grams