Distillation
November 26, 2015
Nicholas Colaco
100978557
Thursday PM lab
Results and Observations
The unknown sample number that we used was 37.
The first tube started dripping at 64○C.
Table 1:Temperature ranges for each test tube (5mL of solution)
Test Tube Number
Temperature Range (○C)
1
64-66
2
66-68
3
68-69
4
69-69
5
69-70
6
70-70
Table 2: Water solubilities, refractive indicies, and ceric ammonium nitrate test results for test tube 2 and 5
Test Tube Number
Water Solubility
Refractive Indicies
Ceric Ammonium Nitrate complex
2
Water mixed therefore miscible
-1.31 refractive index
-turned red therefore alcohol present
5
Water mixed therefore miscible
-1.35 refractive index
-turned red therefore alcohol present
Discussion
Table 3: Possible unknown solvents boiling points, refractive indicies and water solubility’s
Solvent
Boiling Point (○C)
Refractive Index (nD)
Water Solubility
n-Hexane
69.0
1.3749
Insoluble
Methanol
64.7
1.3284
Soluble
Ethanol
78.5
1.3616
Soluble
Water
100
1.3330
soluble
The purpose of the lab is to separate a mixture containing two unknown compounds using fractional distillation. The unknown compounds will then be determined using four different tests: boiling points, water solubility’s, refractive indicies, and ceric ammonium nitrate complex formation. By comparing the results of these tests, the compounds will be able to be determined.
Fractional distillation is used when the vapor pressures of the two components of a mixture are too close to make simple distillation ineffective. A VIGREUX column is used to distill the mixture containing the two compounds (A and B). Both components will boil out of the flask in relative quantities based on Raoult’s law.
According to Raoult’s law the partial vapor pressure of a volatile compound is equal to its vapor pressure multiplied by its mole fraction. The mixtures will boil out of the...