An antifreeze solution is prepared containing 40.0 g of ethylene glycol (molar mass = 62.0 g/mol) in 60.0 g of water. Calculate the freezing point of this

solutions A.-20.1°C B.0.518°C C.20.1°C D.120.1°C

delta T = Kf*m

Find mols:
mols = grams ethyl/molar mass = ?

Find molality:
m = molality = mols/kg solvent

Plug m and Kf(1.86) into the delta T formula and solve for delta T. Then subtract that from zero to find the new freezing point.

-20.1⁰C

To calculate the freezing point of a solution, you need to use the equation:

△Tf = Kf · molality

where △Tf is the change in freezing point, Kf is the cryoscopic constant for the solvent (water in this case), and molality is the molal concentration of the solute (ethylene glycol).

First, let's determine the moles of ethylene glycol:

moles of ethylene glycol = mass / molar mass
moles of ethylene glycol = 40.0 g / 62.0 g/mol
moles of ethylene glycol = 0.645 mol

Next, let's calculate the molality of the solution:

molality = moles of solute / mass of solvent (in kg)
molality = 0.645 mol / 0.060 kg (since 60.0 g = 0.060 kg)
molality = 10.75 mol/kg

Now that we have the molality, we can calculate the change in freezing point:

△Tf = Kf · molality

The cryoscopic constant (Kf) for water is 1.86 °C/m.

△Tf = 1.86 °C/m · 10.75 mol/kg
△Tf = 19.995 °C

Finally, we can calculate the freezing point:

freezing point of the solution = freezing point of the solvent - △Tf

The freezing point of pure water is 0 °C.

freezing point of the solution = 0 °C - 19.995 °C
freezing point of the solution = -19.995 °C

Therefore, the freezing point of the solution is approximately -20.0 °C.

The correct answer is A. -20.1 °C.