Calculate the freezing point of a 0.75 m solution of Al2(CO3)3.

To calculate the freezing point of a solution, you can use the formula for freezing point depression:

ΔTf = Kf * m

Where:
ΔTf is the change in freezing point,
Kf is the cryoscopic constant of the solvent, and
m is the molality of the solution.

For water (the solvent), the cryoscopic constant (Kf) is 1.86 °C/m.

First, we need to determine the molality (m) of the solution. Molality (m) is defined as the number of moles of solute (Al2(CO3)3) divided by the mass of the solvent (water) in kilograms.

Given:
- Molality (m) = 0.75 m

To calculate the freezing point depression, we need to convert molality into moles of solute:

0.75 m * (2 moles Al2(CO3)3 / 1 kg water) = 1.5 moles Al2(CO3)3 / kg water

The change in freezing point, ΔTf, is given by:

ΔTf = Kf * m

ΔTf = 1.86 °C/m * 1.5 moles Al2(CO3)3 / kg water

ΔTf = 2.79 °C

Therefore, the freezing point of the 0.75 m solution of Al2(CO3)3 is lowered by 2.79 °C.

To calculate the freezing point of a solution, we need to use the formula for the freezing point depression:

ΔT = Kf * molality

where ΔT is the freezing point depression, Kf is the cryoscopic constant, and molality is the concentration of solute in moles per kilogram of solvent.

First, let's determine the molality of the solution. The molality (m) is defined as the moles of solute per kilogram of solvent.

We know the concentration of the solution is 0.75 m, which means there are 0.75 moles of Al2(CO3)3 per kilogram of solvent.

Next, we need to determine the freezing point depression constant (Kf). The Kf value depends on the solvent used. Since we don't have information about the solvent in the question, we cannot determine the exact value of Kf.

Once you have the Kf value for the given solvent, you can substitute the values into the formula and calculate the freezing point depression (ΔT).

Finally, to find the freezing point of the solution, subtract the calculated freezing point depression (ΔT) from the freezing point of the pure solvent.

Note: The ΔT value will be negative because the freezing point depression causes the freezing point to be lower than that of the pure solvent.

delta T = i*Kf*molality