Using the freezing point constant from table 1 calculate the

Using the freezing point constant from table 1, calculate the molar mass of an unknown sunstance, if the freezing point of a solution containing 1.00 g of the unknown in 100g of camphor is 165.4 C.

Table 1 constants:

Camphor:

Freezing Point (C)= 178.4

Kf (C kg/mol)

Solution

Let molality be m

So, dTf = Kf * m

So, (178.4 - 165.4) = 40 * m

So, m = 0.325

So, m = moles / 100 g

So, 0.325 = moles / 0.100

moles = 0.0325 = 1 / molar mass

So, molar mass = 1 / 0.0325 = 30.769 g/mol