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Question by D.A.: What is the molarity of antifreeze in the solution?
A solution is made by dissolving a particular automotive antifreeze (a nonelectrolyte) in water. The solution freezes at -10.4 degrees Celsius. What is the molarity of antifreeze in the solution? Assume that pure water freezes at 0.0 degrees Celsius.

Best answer:

Answer by Chandrakant
If the solution is treated as an ideal solution, the extent of freezing point depression depends only on the solute concentration that can be estimated by a simple linear relationship with the cryoscopic constant:
ΔTF = KF · m · i
ΔTF, the freezing point depression, is defined as TF (pure solvent) – TF (solution).
KF, the cryoscopic constant, which is dependent on the properties of the solvent, not the solute. Note: When conducting experiments, a higher KF value makes it easier to observe larger drops in the freezing point. For water, KF = 1.853 K·kg/mol.[4]
m is the molality (mol solute per kg of solvent)
i is the van ‘t Hoff factor (number of solute particles per mol, e.g. i = 2 for NaCl).
This simple relation doesn’t include the nature of the solute, so this is only effective in a diluted solution. For a more accurate calculation at a higher concentration, Ge and Wang (2010)[5] [6] proposed a new equation: which is complicated.

10.4=1.853XMX2 (vont hoff factor assumed as 2)
M =2.806

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