Experimental report on synthesis of n-butyl acetate
Objectives
This experiment aims to synthesize n-butyl acetate through specific chemical reactions, and conduct in-depth exploration of various indicators and reaction principles in the synthesis process to master relevant organic synthesis experimental skills and theoretical knowledge.

Experimental principle
Esterification reaction between acetic acid and n-butanol under the catalysis of concentrated sulfuric acid to form n-butyl acetate. The reaction equation is: $CH_ {3} COOH + C_ {4} H_ {9} OH\ stackrel {H_ {2} SO_ {4}} {\ rightleftharpoons} CH_ {3} COOC_ {4} {9} + H_ {2} O $. Concentrated sulfuric acid acts as a catalyst to accelerate the reaction rate. At the same time, the reaction is a reversible reaction. In order to improve the yield of n-butyl acetate, measures such as excessive amount of a reactant or timely removal of the water generated by the reaction can be taken.

Experimental instruments and reagents
1. ** Instruments **: round bottom flask, spherical condenser, water separator, thermometer, separation funnel, distillation device, etc.
2. ** Reagents **: glacial acetic acid, n-butanol, concentrated sulfuric acid, sodium carbonate solution, anhydrous magnesium sulfate, etc.

Experimental steps
1. ** Esterification reaction **: In a dry round-bottom flask, add a certain amount of n-butanol, glacial acetic acid and concentrated sulfuric acid in turn, shake well and put into the zeolite, and connect the spherical condenser and the water separator. Heat reflux, pay attention to observe the water level change in the water separator during the reaction. When there is obvious stratification in the water separator and the water layer does not increase, stop heating. At this time, the reaction is basically completed.
2. ** Crude product separation **: After cooling the reaction solution, transfer it to the separation funnel. First add an appropriate amount of water to wash, remove most of the sulfuric acid and unreacted acetic acid, and separate the lower aqueous phase after stratification. Then wash with sodium carbonate solution until the organic phase no longer makes the pH test paper acidic to remove the residual acid. This is followed by a wash with saturated salt water to reduce the solubility of the ester in water and reduce losses. Finally, the aqueous phase is separated to obtain crude n-butyl acetate.
3. ** Drying and Distillation **: Transfer the crude product to a dry conical flask and add anhydrous magnesium sulfate to dry for a period of time. Carefully transfer the dried liquid to a distillation flask for distillation. Collect the fraction within the specified temperature range, which is the refined n-butyl acetate.

Experimental Results and Discussion
1. ** Yield Calculation **: By measuring the volume or mass of the final n-butyl acetate, the yield is calculated according to the reaction equation and the initial reactant dosage. The actual yield is compared with the theoretical yield, and the reasons for the high and low yield are analyzed. If the yield is low, the possible reasons are that the reaction does not reach equilibrium, the loss of reactants (such as the dissolution loss of esters during washing), the occurrence of side reactions, etc.; if the yield is high, the measurement error or the possible increase in quality due to the mixing of impurities should be considered.
2. ** Product purity analysis **: The purity of the product can be identified by physical methods (such as measuring refractive index) or chemical methods (such as infrared spectroscopy analysis). If the refractive index value is compared with the standard value, if the deviation is large, it indicates that the product may contain impurities; the characteristic absorption peak in the infrared spectrogram can determine whether there is a target functional group in the product, and whether there are other impurities corresponding to the functional group absorption peak.
3. ** Discussion on Optimization of Reaction Conditions **: Analyze the influence on the reaction from the aspects of catalyst dosage, reactant ratio, reaction time and temperature. For example, appropriately increasing the amount of concentrated sulfuric acid can speed up the reaction rate, but too much may lead to more side reactions; Change the ratio of n-butanol to glacial acetic acid to study which ratio is more conducive to improving the yield; Prolong or shorten the reaction time, increase or decrease the reaction temperature, observe the effect on the yield and product purity, so as to find the better reaction conditions.

Experimental Conclusion
Through this experiment, n-butyl acetate was successfully synthesized, and the synthesis process was systematically studied. The basic principle, operation method and product analysis and identification methods of n-butyl acetate synthesis were mastered. At the same time, through the analysis of the experimental results, the factors affecting the reaction yield and product purity were clarified, which provided experience and reference for similar organic synthesis experiments and process optimization in the future. In future experiments, the reaction conditions can be further optimized, the product yield and purity can be improved, and the organic synthesis experimental skills can be improved.