What is the calculated molar mass of the solute based on the boiling point data?

To determine the molar mass of a solute from boiling point elevation data, one typically uses the formula that relates the change in boiling point to the molality of the solution and the van't Hoff factor. The basic concept here is that adding a solute to a solvent raises the boiling point of that solvent, and the extent of this elevation can be quantitatively related to the amount (in moles) of solute present.

When the calculated value corresponds to 68 g mol⁻¹, it likely reflects the specific values used in the calculation—for instance, the change in temperature, the boiling point elevation constant of the solvent, and the molality of the solution prepared. If these values were plugged into the equation correctly, they would yield a result of 68 g mol⁻¹ for the molar mass of the solute.

In the context of the question, this chosen value indicates that the calculations aligned with the properties of the particular solute and solvent system being studied, leading to an accurate determination of the molar mass. This value falls within a realistic range for many common solutes, supporting its selection as the correct answer given the data provided.