Chemistry question

Question

"Determine the mass of a 1.15L aqueous solution of sucrose (C₁₂H₂₂O₁₁) that is isotonic with seawater given the average osmotic pressure of seawater is 30.0 atm at 25°C."

Answer 1

π = iMRT

π = osmotic pressure = 30.0 atm

i = van't Hoff factor = 1 for sucrose as it is a non electrolyte

M = molarity = moles sucrose / liter solution = ?

R = gas constant = 0.0821 Latm/Kmol

T = temperature in Kelvin = 25º + 273 = 298K

Solving for M:

M = π / (i)(R)(T)

M = 30.0 / (1)(0.0821)(298)

M = 1.23 moles / liter

Since we have 1.15 L we have 1.15 L x 1.23 moles / L = 1.41 moles of sucrose

Molar mass sucrose = 342 g / mol

Mass of sucrose = 1.41 moles x 342 g / mol = 482 g sucrose