The molar mass of a solid as determined by freezing point depression is 10% higher than the true molar mass.Which of the following experimental errors could not account for this discrepancy?
A)Not all the solid was dissolved.
B)More than the recorded amount of solvent was pipetted into the solution.
C)The solid dissociated slightly into two particles when it dissolved.
D)Some solid was left on the weighing paper.
E)Before the solution was prepared,the container was rinsed with solvent and not dried.

Question

Quizplus · Accepted Answer

Option C (The solid dissociated slightly into two particles when it dissolved) would actually lead to a lower calculated molar mass, not a higher one, because the presence of more particles in solution would increase the freezing point depression more than expected for a non-dissociating solute.

The Molar Mass of a Solid as Determined by Freezing