Data:

freezing point of pure cyclohexane: 6.0 degrees celcius

Freezing point of unknown soluton: 1.6 degrees celcius

weight of cyclohexane: 40.0231g=0.0400231 kg
weight of unknown solute: 0.4872 g
K_f_ of cyclohexane: -20.00 degrees Celciusx kg/mole

questions:
1. what is the change in freezing point of cyclohexane?
2. what is the molarity of the solution?
3. what is the moleculr weight of the unknown solute?

1. normal freezing point - freezing point soln = change.

2. I think you want molality and not molarity. delta T = Kf*m. Solve for m = molality.
3. molality = moles/kg solvent
Solve for moles.
Then moles = grams/molar mass. Solve for molar mass.

To answer the questions, we will use the concept of freezing point depression and the equations related to it. Freezing point depression is a colligative property that depends on the number of solute particles in a solution.

1. The change in freezing point (∆Tf) can be calculated using the equation:

∆Tf = Kf * m

where Kf is the cryoscopic constant of the solvent and m is the molality of the solution. In this case, the cryoscopic constant of cyclohexane (Kf) is given as -20.00 degrees Celsius x kg/mole.

First, convert the weight of cyclohexane and the unknown solute to moles:

Moles of cyclohexane = weight of cyclohexane / molecular weight of cyclohexane
Moles of unknown solute = weight of unknown solute / molecular weight of unknown solute

Since the weight of cyclohexane is given as 40.0231 g and the molecular weight of cyclohexane is 84.16 g/mol, we can calculate:

Moles of cyclohexane = 40.0231 g / 84.16 g/mol

2. The molarity of the solution can be calculated using the equation:

Molarity (M) = moles of solute / volume of solution (in liters)

To calculate the moles of solute, we need to know the volume of the solution. Without this information, we cannot provide an accurate answer.

3. The molecular weight of the unknown solute can be calculated using the equation:

Molecular weight of unknown solute = weight of unknown solute / moles of unknown solute

Since the weight of the unknown solute is given as 0.4872 g, and we calculated the moles of the unknown solute in question 1, we can solve for the molecular weight:

Molecular weight of unknown solute = 0.4872 g / (moles of unknown solute)

By substituting the value of moles of the unknown solute calculated in question 1, we can find the molecular weight of the unknown solute.