Chemistry/Distillation

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SCIENCE 8 EXPERIMENT


DISTILLATION


Purpose: To learn how to set up a distillation apparatus and separate a mixture of methanol and methylene blue dye by the method of distillation.


Material:

hot plate
U–shaped tube with rubber stopper and 125 mL erlenmeyer flask
400 mL beaker and large test tube
stand and test tube clamp
solution of methylene blue dye dissolved in methanol
ice water


Procedure:
1. Set up a distillation apparatus as shown in the following diagram.

2. Use a 100 mL graduated cylinder to measure 50 mL of the methylene blue solution. Remove the rubber stopper from the flask, pour in the 50 mL portion of methylene blue solution and replace the stopper.

3. Turn on the hot plate and record what you see until the distillation is ended.

Discussion:
1. Describe the solution at the start of the experiment.


2. Describe
(a) the distillate (that is, the liquid which distills into the test tube), and,
(b) the residue in the flask


3. What evidence do you have that the distillation process separated the solvent and the solute?


4. Identify the two changes of state that occurred in this experiment and describe where in the distillation apparatus each change of state occurred.


5. What was the purpose of the ice water?