Lab: Chemistry
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At the end of this lab, students should know...
The vapor pressure of a pure substance is the pressure exerted by the gaseous phase on the liquid or solid phase in a closed container.
A liquid boils when the vapor pressure of the liquid is equal to the atmospheric pressure.
A miscible solution contains substances that can form a homogeneous solution, whereas an immiscible mixture is composed of substances that cannot be mixed, and therefore form a heterogeneous mixture.
In an immiscible mixture, the sum of the individual pure component vapor pressures equals the total vapor pressure of the solution.
The steam distillation setup has a water reservoir, which lowers the boiling point of the mixture by forming an immiscible mixture with the organic compounds.
Source: Lara Al Hariri at the University of Massachusetts Amherst, MA, USA
Here, we show the laboratory preparation for 10 students working in pairs, with some excess. Please adjust quantities as needed.
2 Lab stands |
1 Stir plate |
1 Heating mantle |
1 Temperature controller |
1 500-mL round-bottom flask with cork stand |
1 Distilling head |
1 Condenser |
1 Connecting tube |
1 Separatory funnel |
1 Claisen adapter |
1 Thermometer adapter |
1 Thermometer |
1 Small spatula |
1 Stir bar |
4 Joint clips |
2 Pieces of rubber tubing |
1 Tube of vacuum grease |
2 Standard clamps |
1 Ring support |
1 Conical funnel |
1 250-mL round-bottom flask and cork stand |
1 100-mL graduated cylinder |
2 150-mL beakers |
1 125-mL Erlenmeyer flask |
1 Filter paper |
1 500-mL beaker |