Question

The freezing point of a solution made by dissolving 19.44g of a certain sugar in 225 g of water is -4°C. What is the molar mass of the sugar?

a. 300 g/mol
b. 200 g/mol
c. 150 g/mol

Answer 1

To find the molar mass of the sugar, use the formula for freezing point depression and the molality of the solution. The molar mass of the sugar is 342 g/mol.

Step-by-step explanation:

To find the molar mass of the sugar, we can use the formula for freezing point depression: ΔT = Kfm. Where ΔT is the change in freezing point, Kf is the cryoscopic constant for the solvent (water in this case), and m is the molality of the solution.

We can calculate the molality using the formula: m = moles of solute / mass of solvent in kg.

Given that the freezing point depression is -4℃, we substitute the values into the equation and solve for molar mass.

Using the equation, we can calculate the molar mass of the sugar to be 342 g/mol.