van't_Hoff_general_solution

Question

A solution of cane sugar ( molar mass is 342g per mole) containing 17.8g per L has an osmotic presssure 1.2 atm . Calculate the temperature of the soultion .( where R= 0.082L atm per mol per K). I am getting 281.4K does it is correct.

Answer 1

The equation for osmotic pressure is π = iMRT

π = osmotic pressure = 1.2 atm

i = van't Hoff factor = 1 for cane sugar (a non electrolyte)

M = molarity = moles/liter = 17.8 g/342 mol/1 L = 0.0520 M

R = gas constant = 0.0821 Latm/Kmole

T = temperature = ?

Solving for T, we have T = π/(i)(M)(R) = 1.2 atm/(1)(0.0520K)(0.0821 Latm/Kmol)

T = 281K (t0 3 significant figures) = 280K (to 2 significant figures)

You are correct