Simple Distillation of Ethyl Acetate contaminated with Methyl Violet

Simple Distillation of Ethyl Acetate contaminated with Methyl Violet
Operational OrganicChemistry A Problem Solving Approach to the Laboratory Course, 4th edition, by John Lehman, Experiment 4, OP-30 pg 710-719

I. Introduction
The students will use the distillation method to extract pure Ethyl acetate by using the distillation equipment. The distillation is the process of vaporizing a liquid mixture in one vessel and condensing the vapors into the receiver.
II. Experimental procedures.
1. Safety Information: Minimize contact with the liquid and do not breathe its vapors. Inhalation of these vapors can be dangerous. We will be handling equipment with heat source, so do not let your skin contact with the equipment that might cause physical burn. Also EtoAc is very flammable, dries out the skin and inhaling large quantities can cause dizziness. Handle with care.
2. Stepwise Procedures:
a) We will be using 10 mL of the ethyl acetate mixture. Measure accurately and record the volume by using the 10mL graduated cylinder.
b) Use 25mL round bottom flask in your organic kit. Make sure to use 2-3 boiling chips and stopcock grease on all ground class joints.
c) Get out the condenser from the organic kit. Also get 3 way connector and the vacuum adapter. You will need to receive in a 10mL clean graduated cylinder. Also get 2 rubber hoses.
d) Get the heating mantle and place the 25mL round bottom flask with the ethyl acetate and boiling chips in the mantle. Secure the flask. Then attach the 3 way connector to the top of the flask using stopcock grease. On top of the 3 way connector, place the thermometer adapter also by using the grease. Use blue clamp to secure the thermometer adapter. Use a Hg thermometer to record the temperature. Make sure the top of the Hg bulb is even with the bottom of the sidearm of the 3 way connector. Attach the condenser using a stop cock grease and a blue clamp to secure the condenser. Attach rubber hoses to the condenser. One hose should connect from the water source to the bottom nipple of condenser and the other hose should connect from the top nipple of the condenser and drain into the sink. Vacuum adapter should be attached to the bottom of the condenser using the grease with blue clamp to secure it. Receive into 10mL graduated cylinder.
e) Once you have everything, get instructor’s approval to go ahead with the experiment.
f) Begin heating by setting the variac to high or 9. Collect ethyl acetate until the stillpot becomes almost dry. Record the temperature when you have received 5 mL of sample and continue heating. This temperature should be the bp of the purified ethyl acetate.
g) When finished, record the volume of purified ethyl acetate and save some of it in a vial. Label the vial with name and simple distillation and place them on the yellow cabinet.
h) In Results section, calculate the % recovery of purified ethyl acetate.
i) Clean up. Get approval from instructor before putting the organic kit back into the box.

100% Ethyl Acetate(Clear, Colorless) Structure:

V. Theory and Conclusion In this lab we used a technique known as simple distillation. Simple distillation is the process by separating volatile substances based on different physical properties. You can do two different simple distillations. The first is a volatile liquid with a nonvolatile impurity. This is possible because one substance will go into the vapor phase and will stay in the boiling pot. This is what we had for the actual experiment. The other one that we can do is when we have 2 liquids that have a boiling point with a 50 to 60 degree Celsius temperature difference. In this method, we can have one liquid go into a volatile state at a low temperature and when all of that has been distilled, you can remove it because the other liquid had not yet gone into the volatile phase and will stay in the boiling pot. The steps for the simple distillation are very simple but putting all the parts together is complex. In order to get a high percent recovery, all the glassware and parts must be set up properly and tightly attached to each other by using stopcock grease and blue clamps. The mercury thermometer placement is extremely important because if the thermometer is too high then the temperature reading will be too low and will give us low percent recovery. The thermometer has to be placed where the top of the thermometer bulb is aligned with the bottom of the sidearm of the stillhead. If it is correctly placed, then all of the thermometer bulb will be moistened by the vapors that are created by the distillate and will give us a high percent recovery. Also we had to understand the boiling point elevation in this experiment because the solution consisted of EtoAc and Methyl violet. Boiling point elevation is a phenomenon that the boiling point of a solution will be higher than the pure solvent. Since we are dealing with two different solvents with different boiling points, it will definitely affect the pot temperature by rising the temperature. So the temperature of the pot will be higher than the temperature around the stillhead. The boiling point of the EtoAc is approximately at 78°C and the recorded boiling point I got from my experiment was 79°C. This result proved that I had put the thermometer in the proper place. We used boiling chips in the experiment, which are made from porous pieces of different materials such as carbon, glass, and alumina. The purpose of boiling chips is to prevent bumping from occurring when heating a liquid substance. Bumping is the process when a liquid is heated to its boiling point and in the process may erupt violently as large bubbles of vapor that the liquid is discharging. Using boiling chips during any distillation method is advised because boiling chips prevents these violent eruptions during boiling process. Also we did not get 100% recovery because in the condenser there is a small lump that collected EtoAc sample before it flowed towards the other flask. We turned off the heat when the liquid sample was almost gone in the 25mL round flask. This meant there were some remnants still left in the original flask which also played a factor towards the result of no 100% recovery. Even with these, I was able to still recover 91% of the distillate.