2025-2026 (CHEM 103) LAB REPORT 8 | PORTAGE
LEARNING| GRADED A+
Chemistry Lab
Report
Experiment # 8
Title: Molecular Mass
Purpose: In this lab we will determine the molar mass of an unknown solute by its
fressinhg point depression.
Procedure:
1. Measure out 10 ml of cyclohexane (the solvent). We will get the molar mass of the
(Solute) of the unknown substance. Pour the cyclohexane into the testtube and fit it
with a stopper. The stopper has a hole for the wire (stirrer) and thermometer.
2. Insert testube into ice (mixture of ice and salt). Create a cold bath and let the
cyclohexane cool down and let the bottom freeze. Wait till there are a nice number of
crystals on the ottom part that are frozen really well.
3. Clamp testube . The initial temperature is 6.6C , read and record temperature every 30
seconds and create a warming plot to see freezing point. 30 seconds-6.6c 120 seconds-
7 C 8 minutes
11.4 C
.
4. Started at 6.6 C fully frozen and leveled off at 6.6 and stayed there after 2 minutes it
started to warm. Now add the unknown solute to cyclohexane which will depress the
dressing point. Weigh out some of the solute at .3014 grams of unknown solute.
5. Swirl around to see flakes floating around. In order for it to be a solute it needs to be
dissolved. Add 10 mo of original solvent (cyclokexane) and stirl until all crystals
