“Proof of Alcohol.” CHM1045L Online Manual. Spring 2009. 26 February 2009
Data
Part I Mass of 10.0 mL graduated cylinder | 39.5763 g | Volume of Ethanol | 2.95 mL | Mass of Ethanol | 2.1367 g | Density of Ethanol | .724 g/mL |
Part II Mass of the 10.0 mL graduated Cylinder | 39.5763 g | Volume of DI Water | 2.95 mL | Mass of DI Water | 2.6766 g | Density of DI Water | .907 g/mL |
Part III Mass of 25 mL graduated cylinder | 60.9571 g | Mass of graduated cylinder with solution | 84.0864 g | Mass of Solution | 23.1293 g | Volume of Solution | 25.0 mL | Density of Solution | .925 g/mL | Mass of Salt | 1.0700 g | Mass of Water Layer | 19.6829 g | Mass of Alcohol Layer | 4.5164 g …show more content…
The experiment went exactly as planned in all three parts. In part I and II of the lab, density of ethanol and water was calculated. The density of water was .907 g/mL and the density of ethanol was .724 g/mL. Since the density of ethanol is less than the density of water, it could be predicted that the ethanol would float on top of the water solution when chemically separated.
For part III of the experiment, ethanol was mixed with an unknown water solution. Ethanol is miscible with water so NaCl, diethyl ether, and sodium acetate were added to chemically separate the alchaol from the rest of the unknown solution. The divided solution was then put into a separatory funnel, and the water part of the solution was drained. This can be done because the ethanol is a clear color and the water was yellowish. The ethanol having a lower density, floated on top of the yellow water layer, so there was a clear line where the two divided. The water layer was drained from the solution leaving just the ethanol in the separatory funnel. Using the drained water layer all of the calculations above could be …show more content…
The measurements of density and water were off. The known density of water is 1.00 g/mL not .907 g/mL and the known density of ethanol is .789 g/mL not .724 g/mL. These errors were made because the mass scale was not calibrated or because a slight error was made reading the volume. It is also likely that an error was made when draining the water layer. It is impossible to tell exactly where the solution switches from water to ethanol, so some ethanol probably got drained with the water layer. This would slightly change the volume and mass of the water layer. However, these mistakes were expected to happen and the lab was still very successful. Every step of the lab went as expected, and even if the numbers are a little incorrect they are very close to what they should