(a) What fraction of the moles of NaCl in this solution exist as ion pairs?
(b) Calculate the freezing point that would be observed for this solution.
density = 1.071 g/cm3 = 1.071 kg/L
molar mass of NaCl = 23 + 35.45 = 58.45 g/mol
Kf of water = 1.86 C/m ---from book
pi = osmotic pressure
Basis : 1 kg of solution
V = vol. of solution = 1 kg / 1.071 kg/L = 0.9337 L
M = molarity = mol NaCl / liter solution
mol NaCl = 0.01(1 kg) (1000g/ 1 kg) ( 1 mol / 58.45 g/mol)
= 0.171 mol
M = 0.171 mol / 0.9337 L
= 0.183 M
pi = iMRT
i = pi / MRT
The expert examines osmotic pressure moles NaCl exists as ion pairs.