CHM125 BASIC ORGANIC CHEMISTRY
LAB REPORT
EXPERIMENT TITLE : EXTRACTION AND DRYING OF AN AQUEOUS SOLUTION
NAME AND : i) NORLIYANA NAFISHA BINTI SULAIMAN
STUDENT ID (2022824116)
ii) NUR SYAZANA BALQIS BINTI ABDUL HALIL
(2022878314)
iii) NUR ALIAH BINTI ZAKARIAH
(2022841098
DATE OF EXPERIMENT: 1st December 2022
DATE OF REPORT SUBMISSION: 8th December 2022
NAME OF LECTURER: Dr. Mohd Fauzi Abdullah
MARKING SCHEME OF THE LABORATORY REPORT
Contains Allocated Given
Mark % Mark
i.Objective 1
ii. Introduction and Hypothesis 2
iii.Materials, Apparatus and Methodology 3
iv. Diagram 2
v. Result and data 4
vi. Calculation 4
vii. Discussion 4
viii. Questions 2
ix. Conclusion 1
x. References 1
xi.Format,quality,spelling,punctuation,grammar 1
TOTAL 25
OBJECTIVES
1. To learn the techniques of separating toluene from water (and other
Inorganic compounds) by extraction.
2. To learn the techniques of drying a dehydrated solution.
INTRODUCTION
The partial removal of a molecular solute from one liquid (usually water) into another
immiscible liquid is call solvent extraction. The technique is use in organic chemistry. In the
laboratory, the two immiscible liquids are shaken thoroughly in a separating funnel fitted
with a good stopper. The tap is open at times during the shaking to release any pressure
caused by solvent vapor. A solvent such as ether is used because its boiling point is low and
it can be distilled from the extracted solution and recycled. In other hands volatile organic
liquids such as ether is dangerously flammable. Although water and ether is immiscible,
water does in fact, dissolve to some extent in ether. Due to this fact ether extracted is
always dried thoroughly with a suitable drying agent (such as anhydrous magnesium
sulphate) before the ether is distilled off. For a given volume of extracting solvent, it is more
efficient to carry out extraction by successive use of equal portions of the solvent rather
than the use of the whole volume in a single extraction.
CHEMICALS:
Toluene solution
Diethyl ether
Anhydrous magnesium sulphate
APPARATUS:
1 separating funnel
1 retort stand
1 100 ml round bottom flask 1 condenser
1 still head
1 thermometer
1 filter paper
1 heating mantle
2 rubber hoses
1 adapter
1 pocket thermometer
PROCEDURE:
1. In a separating funnel,20ml toluene and 15 ml of distilled water mixed.
2. 20 ml diethyl ether mixed and shaked vigorously.The tap opened often during the
shaking to reduce the incorporated steam pressure and continue to shake until the
solution no longer releases pressure(note: when there is no more hissing sound
whwn the tap is open.
3. The tap opened and the diethyl ether with toluene is drained into a dry conical
container.The remaining water layer is used for extra extraction.
4. Another 20 ml diethyl ether added by means of the separating funnel.
5. The mixtures of diethyl ether dried off,with roughly half or one anhydrous spatula of
magnesium sulphate (or anhydrous calcium chloride) toluene (not dissolve the
compound).dry agents filtered out.
6. The techniques of distillation removes toluene from diethyl ether.
Questions:
1. When you are extracting an aqueous solution with an organic solvent,you are
uncertain of which layer in the separatory funnel is aqueous,how would you quickly
sort out the issue.
Add a bit of water from squirt bottle to the separatory funnel.If the top layer is
aqueous ,the water droplets should mix with the top layer and the droplets will look
like it disappears .If the bottom layer is aqueous,the water droplets will fall through
the top layer and mix with it.
2. What is the purpose of using anhydrous magnesium sulphate in the experiment?
Anhydrous magnesium sulphate is used as a drying agent. They are used to remove
any coloured impurities that might contaminate a product.
3. Draw the apparatus needed for extraction.
4.How do you estimate the anhydrous magnesium sulphate added is enough for the solvent
in the experiment?
Before drying agent is added, the organic layer has to be separated from the aqueous
layer .Then add the drying agent if there is a second layer on the bottom.
DISCUSSION :
In this experiment, liquid-liquid extraction is used. Liquid-liquid extraction involves the
separation of the solutes of a liquid solution by contact with another insoluble liquid. Drying
is also involved in this experiment. Drying organic solutions is the process of synthetizing
and isolating and organic compound often results in an organic compound or solution
contaminated with water. In aqueous extraction some water will be transferred into the
organic phase because of partial miscibility of the organic phase and water. This water must
be removed before the required compound can be properly characterized. Drying agent
used is anhydrous magnesium sulphate because it works well with solvent like diethyl ether.
For the result, organic solvent should be the top layer while water will be at the bottom
layer. This is because organic solvent is less dense than water. There are several errors may
occur during this experiment. First, is adding too much of drying agent. This will cause water
and some of the product absorbed. Thus, less product will be gain. Second, is where the
bottle cap is not closed when taking some of drying agent. This will cause the drying agent
to absorb water in air and make the drying agent do not work effectively. To overcome this
error, do not put too much drying agent by adding a little bit at a moment until the solution
become translucent. Second, always close the drying agent container to avoid any moisture
of air will be absorb by drying agent .
CONCLUSION:
As a conclusion, the objective of this experiment was to learn the techniques of separating
toluene from water by extraction and the techniques of drying a dehydrated solution are
met .
REFERENCES
https://orgchemboulder.com/Technique/Procedures/Drying/Drying.shtml
