做实验报告英文

Abstract:
This report details the experimental procedure and results obtained from the synthesis of ethyl acetate, a common ester, through the
esterification reaction between ethanol and acetic acid. The reaction was carried out in the presence of a catalyst, sulfuric acid, to enhance the rate of the reaction. The product was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography-Mass Spectrometry (GC-MS) to confirm its identity and purity.
1. Introduction:
Esters are organic compounds that are formed by the reaction of an alcohol with an acid, typically a carboxylic acid. Ethyl acetate, with the chemical formula C4H8O2, is a widely used solvent in various industries due to its pleasant odor and low toxicity. The synthesis of ethyl acetate is a classic example of an esterification reaction, which can be catalyzed by an acid to proceed more rapidly.
The objective of this experiment was to synthesize ethyl acetate from ethanol and acetic acid using sulfuric acid as a catalyst. The reaction conditions were optimized to achieve maximum yield and purity of the product.
2. Materials and Methods:
Materials:
- Ethanol (99% pure)
- Acetic acid (glacial, 99% pure)
- Sulfuric acid (98% pure)
- Sodium bicarbonate
- Distilled water
- Sodium chloride
- Sodium sulfate
- Sodium hydroxide
- Sodium sulfate anhydrous
- Potassium permanganate
- Chromatographic column (for GC-MS)
- FTIR spectrometer
- Analytical balance
- Magnetic stirrer
- Round-bottom flask (250 mL)
- Glassware (funnel, beaker, graduated cylinder)
- Gas chromatography-mass spectrometry (GC-MS) system
- Fourier Transform Infrared Spectroscopy (FTIR) system
Methods:
2.1. Preparation of Ethyl Acetate:
1. Reagents Preparation:
- Weigh 50 g of ethanol and 30 g of acetic acid into a round-bottom flask.
- Add 0.5 g of sulfuric acid as a catalyst.
2. Reaction:
- Place the flask on a magnetic stirrer and heat the mixture at 60°C for 2 hours.
- Maintain the temperature throughout the reaction period.
3. Separation:
- After the reaction, cool the mixture to room temperature.
- Add 50 mL of water to the flask and stir the mixture for 5 minutes.
- Add 10 g of sodium bicarbonate to neutralize the acid.
- Separate the organic layer from the aqueous layer using a
separatory funnel.
4. Purification:
- Wash the organic layer with water and 10% sodium sulfate to remove impurities.
- Dry the organic layer over anhydrous sodium sulfate.
- Filter the dried product through a funnel lined with filter paper.
5. Characterization:
- Perform FTIR analysis of the synthesized ethyl acetate.
- Perform GC-MS analysis of the synthesized ethyl acetate.
3. Results and Discussion:
3.1. FTIR Analysis:
The FTIR spectrum of the synthesized ethyl acetate showed characteristic peaks at 1735 cm-1 (C=O stretching), 2950 cm-1 (C-H stretching), and 1375 cm-1 (C-O stretching), which are indicative of the presence of an ester functional group. The absence of peaks at 1720 cm-1 (C=O
stretching of acetic acid) and 2980 cm-1 (C-H stretching of ethanol) confirms the conversion of the reactants into ethyl acetate.
3.2. GC-MS Analysis:
The GC-MS analysis of the synthesized ethyl acetate confirmed the presence of the expected molecular ion peak at m/z 88. The fragmentation pattern of the molecular ion was consistent with the structure of ethyl acetate, further confirming the identity of the product.
4. Conclusion:
The synthesis of ethyl acetate from ethanol and acetic acid using
sulfuric acid as a catalyst was successfully achieved in this experiment.
The optimized reaction conditions led to a high yield and purity of the product, as confirmed by FTIR and GC-MS analysis. The experiment provided valuable insights into the esterification reaction and the importance of catalysts in achieving desired results.
5. References:
- Smith, J. M. (2002). Organic Chemistry. New York: McGraw-Hill.
- March, J. (2007). Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (5th ed.). New York: Wiley.
- Smith, M. B., & March, J. (2013). March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (7th ed.). New York: Wiley.。