CM1501 Expt 2
National University of Singapore
CM1501
Organic Chemistry for Engineers
Lab Report
Experiment 2: Separation and Identification of Two Organic Compounds
10th October 2013
Abstract
This experiment involves the separation and identification of 2 organic compounds (1 Neutral Compound and 1 Acidic Compound) in a mixture. Separation techniques used in this experiment include solvent extraction, simple distillation and recrystallization using a suitable solvent determined through a solubility test. The identification method used was through Melting Point Determination. By obtaining data of the melting points of the 2 purified compounds and cross-referencing from a list of possible organic compounds, the 2 organic compounds were identified to be Dibenzalacetone (Neutral) and o-Chlorobenzoic acid (Acidic).
Results
A solubility test was conducted to determine the recrystallization solvent to be used for the 2 compounds. The solvents used in the test were water and ethanol, both under room temperature and near boiling conditions. The results are tabulated in Table 1 below.
Table 1: Results for Solubility Tests
Solvent
Neutral Compound
Acidic Compound
Room Temp
Hot
Room Temp
Hot
Water
Not Soluble
Not Soluble
Not Soluble
Not Soluble
Ethanol
Not Soluble
Soluble
Not Soluble
Soluble
From the results in Table 1, the method of recrystallization using 100% ethanol is determined to be most suitable for both compounds.
Using 100% ethanol as the solvent for recrystallization, the purified compounds were obtained in the form of crystals. Table 2 below summarises the primary data of the 2 purified compounds.
Table 2: Primary Data of Purified Compounds
Neutral Compound
Acidic Compound
Appearance
Yellow crystals
White powder
Mass obtained (g)
0.6844
0.5893
After obtaining the purified compounds, their melting points are then determined. The experimentally obtained melting point data are then checked against a list of possible compounds
CM1501
Organic Chemistry for Engineers
Lab Report
Experiment 2: Separation and Identification of Two Organic Compounds
10th October 2013
Abstract
This experiment involves the separation and identification of 2 organic compounds (1 Neutral Compound and 1 Acidic Compound) in a mixture. Separation techniques used in this experiment include solvent extraction, simple distillation and recrystallization using a suitable solvent determined through a solubility test. The identification method used was through Melting Point Determination. By obtaining data of the melting points of the 2 purified compounds and cross-referencing from a list of possible organic compounds, the 2 organic compounds were identified to be Dibenzalacetone (Neutral) and o-Chlorobenzoic acid (Acidic).
Results
A solubility test was conducted to determine the recrystallization solvent to be used for the 2 compounds. The solvents used in the test were water and ethanol, both under room temperature and near boiling conditions. The results are tabulated in Table 1 below.
Table 1: Results for Solubility Tests
Solvent
Neutral Compound
Acidic Compound
Room Temp
Hot
Room Temp
Hot
Water
Not Soluble
Not Soluble
Not Soluble
Not Soluble
Ethanol
Not Soluble
Soluble
Not Soluble
Soluble
From the results in Table 1, the method of recrystallization using 100% ethanol is determined to be most suitable for both compounds.
Using 100% ethanol as the solvent for recrystallization, the purified compounds were obtained in the form of crystals. Table 2 below summarises the primary data of the 2 purified compounds.
Table 2: Primary Data of Purified Compounds
Neutral Compound
Acidic Compound
Appearance
Yellow crystals
White powder
Mass obtained (g)
0.6844
0.5893
After obtaining the purified compounds, their melting points are then determined. The experimentally obtained melting point data are then checked against a list of possible compounds