Please solve
80. If density of 2 molal sucrose solution is 1.4 gm/mL at $25° C$, find osmotic pressure.
(1) 4.06 atm 
(2) 2 atm
(3) 40.6 atm
(4) 3.4 atm

Dear student,
2 molal solution means 1000g solvent contains 2 moles sucrose.
It means 1000g solvent contains 2x392 = 784g sucrose
Mass of solution = 1784 g.
Volume of solution  = 1784/1.4 = 1274 mL
Molarity of solution  = 2/1.274 = 1.57 M

Osmotic pressure = CRT
Osmotic pressure = 1.57x0.0821x298 = 40.6 atm

Hope it helps
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