Experiment on alkaline hydrolysis of ethyl acetate

1. Purpose of the experiment
The purpose of this experiment is to deeply understand the principle, process and influencing factors of the alkaline hydrolysis of ethyl acetate (Base Hydrolysis), master relevant experimental operation skills, and learn to obtain reaction kinetic parameters through experimental data processing.

2. Experimental principle
The hydrolysis reaction of ethyl acetate occurs under alkaline conditions. The reaction equation is:\ (CH_3COOC_2H_5 + NaOH\ righlongtarrow CH_3COONa + C_2H_5OH\). This reaction is a second-order reaction, and the reaction rate is proportional to the product of the concentration of ethyl acetate and sodium hydroxide. In the reaction process, with the passage of time, the concentration of the reactants is continuously reduced, and the concentration of the product is gradually increased. By measuring the change of the concentration of a certain substance in the solution at different times, the kinetic properties of the reaction can be studied.

III. Experimental instruments and reagents
1. ** Instruments **: constant temperature water bath pot, pipette, burette, conical bottle, stopwatch, thermometer, etc.
2. ** Reagents **: ethyl acetate, sodium hydroxide standard solution, phenolphthalein indicator, etc.

IV. Experimental steps
1. ** Preparation work **
- Adjust the constant temperature water bath pot to the specified temperature to ensure that the temperature is stable.
- Accurately measure a volume of sodium hydroxide solution of known concentration with a pipette, put it in a clean conical flask, and preheat the conical flask in a constant temperature water bath.
2. ** REACTION START **
- Measure a volume of ethyl acetate with another pipette, quickly add it to the conical flask containing the sodium hydroxide solution, and at the same time start the stopwatch to record the reaction time.
- Immediately shake the mixed solution to allow the reaction to proceed fully.
3. ** Sample Collection and Titration **
- At different time points after the start of the reaction, accurately absorb a certain volume of the reaction mixture with a pipette and quickly add it to the conical flask pre-filled with excess hydrochloric acid standard solution to terminate the reaction.
- Add a few drops of phenolphthalein indicator to the above conical flask and titrate the excess hydrochloric acid with sodium hydroxide standard solution until the solution appears reddish and does not fade within half a minute. Record the volume of the consumed sodium hydroxide standard solution.
4. ** Repeat the experiment **
- Repeat the above experimental steps at least twice to ensure the accuracy and reliability of the experimental data.

V. Record and Processing of Experimental Data
1. ** DATA RECORD **
Record the volume of sodium hydroxide standard solution consumed at different reaction time points in each experiment, as well as the corresponding reaction time.
2. ** DATA PROCESSION **
- Calculate the concentration of ethyl acetate or sodium hydroxide in the solution at different time points according to the reaction principle and titration data.
- Draw the concentration-time curve with time as the abscissa and the concentration of the reactants as the ordinate.
- Calculate the kinetic parameters such as the reaction rate constant by linear fitting of the experimental data or other suitable mathematical processing methods.

VI. Precautions
1. During the experiment, the reaction temperature should be strictly controlled to ensure that the temperature of the constant temperature water bath is stable, because the temperature has a great influence on the reaction rate.
2. The use of pipette and burette should be standardized to ensure the accuracy of measurement and titration.
3. After the reaction starts, the operation should be rapid to minimize the error caused by the operation time is too long.
4. During titration, attention should be paid to observe the color change of the solution and accurately judge the titration endpoint.

7. Results and Discussion
1. ** Experimental Results **
According to the experimental data processing results, the reaction rate constant, reaction order and other kinetic parameters of the hydrolysis reaction of ethyl acetate alkali were obtained.
2. ** RESULTS ANALYSIS AND DISCUSSION **
- Compare the experimental results with theoretical values or literature values, and analyze the reasons for possible deviations, such as experimental operation errors, instrument accuracy, temperature fluctuations, etc.
- Discuss the effects of reaction temperature, initial concentration of reactants and other factors on the reaction rate, and conduct in-depth analysis in combination with experimental data and chemical kinetics theory.
- Think about how to improve experimental methods or experimental devices to improve the accuracy and reliability of experimental results.

Through this experiment, we have a more intuitive and in-depth understanding of the important chemical reaction of alkaline hydrolysis of ethyl acetate. At the same time, we have also exercised experimental operation skills and data processing capabilities, which lays a foundation for further research on chemical kinetics related issues.