Experiment 2: Determination of the Identity of an Unknown Liquid

1168 WordsOct 22, 20135 Pages
The purpose of this experiment is to identify an unknown substance by measuring the density and boiling point. I will be able to conclude which substance is my own from a list of known options stating what its real boiling point and density is. My given unknown liquid code is G9R. This liquid is clear, has a fluid consistency similar to water, and has a strong odour that reminds me of alcohol. Density using a graduated cylinder: Trial 1 Trial 2 Trial 3 Volume of liquid (mL) 15.0mL 30.0mL 45.0mL Mass empty cylinder (g) 73.4g N/A N/A Mass cylinder + liquid (g) 85.1g 97.2g 108g Mass liquid (g) 11.7g 23.8g 34.6g Density of liquid (g/mL) 0.78g/mL 0.79g/mL 0.77g/mL Trial 1: D=m/v Trial 2: D=m/v Trial 3:…show more content…
8. In order confidently determine what substance my “G9R” was I would have to do over the boiling point experiment a couple of more times. I would turn the gas off and take the Bunsen burner away from the apparatus when the stream of bubbles started coming out from the mouth of the capillary tube. This would allow me to correctly determine when the atmospheric pressure was equal to the vapour pressure. I can narrow down my unknown substance to either Ethanol or 2-proponal. Ethanol’s density is only 0.001g/mL higher than my own measurements, but its boiling point is 8.4̊C lower than GNR’s. Whereas 2-proponal’s density is off by 0.003g/mL and its boiling point is only off by 4.5̊C. If I were to make an educated guess I would lean more towards Ethanol. Both the precision and accuracy of my data was far greater in density than in boiling point and Ethanol’s density is closer to GNR’s than any other substance. Works Cited Olmsted, John III; Williams, Greg; Burk, Robert C. Chemistry, 1st Canadian ed.; John Wiley and Sons Ltd: Mississauga, Canada, 2010, pp 399 - 406 Koczanski, Krystyna; Xidos, James D. CHEM 1300 Laboratory Manual; UMSU Copy Centre: Winnipeg, MB, Canada, 2013, pp
Open Document