So I've got this problem:
The freezing point of water in equilibrium with ethyl ether is -3.853°C.
The freezing point of water in equilibrium with a solution of 10.5g of the hydrocarbon N in 100g of ether is 0.232°C higher that the other case (so, -3.621°C).
What's the mass percentage of ether in a solution near the freezing point?
What's the molecular weight of N?
N is not soluble in water and the solubility of the ether doesn't change with the temperature.
Kcr for water is 1.86.
The first part is easy:
I calculate m from [tex]\Delta T = K_{cr}*m[/tex]
and I get m=2.06 mol/kg
2.06 moles of ethyl ether are 153.18g and the mass percentage is 13.28%.
I cannot understand the second part.
If I apply the same equation with a different ΔT I get m=1.947mol/kg.
But I know that the solution is made by 100g of ether, so:
[tex]\frac{1.35mol}{x kg} = 1.947[/tex]
x = 693g (water).
The solution is 693g water, 100g ether, 10.5g N.
I can get the mass percentage but I don't know how to go on with the problem.
Can you help me?
Thank you