Colligative Properties, Freezing Point Depression - Chemistry Lab

[jallison]

Colligative Properties, Freezing Point Depression -- Chemistry Lab

Homework Statement

In an attempt to hurry the experiment along a student did not completely dissolve the unknown nonelectrolyte. Will the freezing point depression of the solution be larger, unaffected, or smaller compared to if the compound was dissolved completely? Will the calculate molar mass be of the unknown be larger, unaffected, or smaller compared to if the compound was dissolved completely?

A lazy student neglected to stir the contents of the test tube when attempting to freeze the solution of the unknown electrolyte. This allowed the solution to undergo supercooling. Will the freezing point depression of the solution be larger, unaffected, or smaller compared to a properly stirred solution?Will the calculated molar mass of the unknown be be larger, unaffected, or smaller compared to a properly stirred solution?

The van't Hoff i factor for an aqueous solution of a weak monoportic acid was measured as 1.26. What is the percent ionization of this acid in the solution?

Homework Equations

ΔT_fp= imK_(fp)
where ΔT_fp is the change in the freezing point, i is the van't Hoff's factor (number of particles) and k is the freezing point depression of solute

molar mass = (g solute/kg solvent)/ΔT_fp/iK_fp

The Attempt at a Solution

I am really not sure. Any help would be appreciated.

 

[Asim Riaz]

For the first question, if the compound was not dissolved completely, the freezing point depression would be smaller. The calculated molar mass of the unknown would also be smaller. For the second question, if the solution was allowed to undergo supercooling, the freezing point depression would be larger. The calculated molar mass would also be larger. For the third question, the percent ionization of this acid in the solution can be calculated using the following equation: Percent Ionization = (i - 1) / i x 100. In this case, the percent ionization would be 26%.