Reaction: Place 6 1 g of benzoic acid and 20 mL of methanol in a 100-mL round- bottomed Shake the funnel to extract methyl benzoate and benzoic acid into the MECHANISM (Fischer esterification) O materials and products (equation )
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[PDF] Methyl benzoate fischer esterification lab report - Squarespace
Methyl benzoate fischer esterification lab report Back to Table of Contents I Summary In this experiment you will prepare methyl benzoate by reacting benzoic
[PDF] Methyl benzoate - classes link 1
This Fischer esterification reaction reaches equilibrium after a few hours of In this experiment you will prepare methyl benzoate by reacting benzoic acid with In addition to the requirements listed in the syllabus for creating a lab report, your
[PDF] Lab5 procedure esterification
Reaction: Place 6 1 g of benzoic acid and 20 mL of methanol in a 100-mL round- bottomed Shake the funnel to extract methyl benzoate and benzoic acid into the MECHANISM (Fischer esterification) O materials and products (equation )
[PDF] Lab9 methyl benzoate handout1
Example: esterification of benzoic acid to methyl benzoate MECHANISM ( Fischer esterification) reaction to give a high yield; the equilibrium must be shifted toward the products: the desired ester, and water This can products ( equation)
[PDF] 5310 F17 Experiment 5: Fischer Esterification - MIT OpenCourseWare
Fischer Esterification: The Organic Synthesis, Isolation, Purification, and Concentrated sulfuric acid is used in this lab and causes severe burns on skin and chemistry results to determine the structure and identity of your unknown sample
[PDF] 5310 F17 Experiment 5: Fischer Esterification - MIT OpenCourseWare
Fischer Esterification: The Organic Synthesis, Isolation, Purification, and Concentrated sulfuric acid is used in this lab and causes severe burns on skin and chemistry results to determine the structure and identity of your unknown sample
[PDF] Esterification Lab Report - teachmeeduvn
22 sept 2008 · LAB REPORT ON A FISCHER ESTERFICATION ESSAY 848 WORDS ONE PART OF CHEMISTRY ESTERIFICATION METHYL BENZOATE
[PDF] Lab 1: Synthesis
Lab Report Components: The following must be Esters are produced by the reaction between alcohols and carboxylic acids For example, reacting Then add 2 drops of concentrated sulfuric acid to the tube a Caution: Concentrated
[PDF] ESTERIFICATION OF CARBOXYLIC ACIDS FOR - CORE
1 août 2019 · Conversion of Benzoic Acid to Methyl Benzoate 10 i Reaction Scheme Results 50 Discussion 55 Chapter 5: Conclusions and Future Work derivatization for the purpose of gas chromatography is Fischer Esterification
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Lab5: Preparation of Methyl Benzoate Reaction: Place 6.1 g of benzoic acid and 20 mL of methanol in a 100-mL round-bottomed flask, and carefully pour 2 mL of concentrated sulfuric acid down the side of the flask. Swirl the flask to mix the reage nts, attach a refl ux condenser, and gently heat the m ixture at re flux for 45 min. (Power controller setting ~ 6. Boiling chips can be used for the reaction.) Work-up/Extraction: Cool the solution and transfer it to a separatory funnel containing 50 mL of water. Rinse the flask with 40 mL of dichloromethane, and add the rinsing to the separatory funnel. Shake the funnel to extract methyl benzoate and benzoic acid into the dichloromethane layer (bottom); vent the funnel often. Remove the organic and aqueous layers and wash the organic layer with a 25-mL portion of water. Remove the organic-layer (bottom) and wash with 25 mL of 0.6 M aqueous sodium bicarbonate. CAUTION: foaming may occur. Swirl the open funnel for a few seconds to a ssure that no vigorous rea ction occ urs; then shake the st oppered funnel with frequent venting. Separate the organic (bottom) layer. Test the remaining (top) aqueous layer to see that it is basic to litmus paper (pH 7-8, dark green). If not, repeat the washing of the organic layer with an additional 25-mL portion of aqueous sodium bicarbonate. Combine this with the first bicarbonate washing and SAVE THE SOLUTION. Wash the dichloromethane layer with a 25-mL portion of satura ted sodi um chloride, then dry the dichloromethane solution with anhydrous magnesium sulfate. Purification/Solvent removal: Remove the drying agent by gravity fi ltration into a 100-mL round-bottomed flask. Set up a simple distillation apparatus using the 100-mL flask, as the pot. (Since dichloromethane is very volatile, cool the receiving flask, and a power controller setting at, or bel ow 3). Remove the dichloromethane by dis tillation and place the distillate (the dichloromethane in the receiver) in the waste dichloromethane recovery bottle. Purification of the product (PhCOOMe) by distillation: Transfer the crude methyl benzoate into a 50-mL round-bottomed flask, and setup an apparatus for simple distillation. Distill the ester using an air-cooled condenser (this means NO WATER goes through, disconnect the tubing) rather than a water-cooled condenser (which can crack because of the high boiling point of the ester). [Power controller setting at 10. You can/should use aluminum foil and glass wool to insulate the still head.] Collect the material boiling above 190o C in a weighed receiver, and calculate the yield. Methyl benzoate should be disposed into the non-halogenated (acetone) waste container. Recovery of unreacted benzoic acid: [Note: this is very similar to the extraction lab] This step should be conducted during the simple distillation removing CH2Cl2. Recover the unchanged benzoic acid from the aqueous sodium bica rbonate washi ng by carefully acidifying the ba sic solution with concentra ted HCl. Cool the s olution in ice and add the HCl dropwis e since t he reaction is exothermic and foaming occurs (CO2 evolution). Collect the precipitate of benzoic acid by vacuum filtration. Determine the weight of the dry benzoic acid and calculate the theoretical yield of methyl benzoate based on the weight of benzoic acid with which you started (6.1 g) less the weight of benzoic acid recovered. Turn in the product into the labeled container. TIPS: - During the extractions, make sure you know which layer you want. In doubt?? SAVE EVERYTHING!! - Don't forget to answer the problem assignment in your notebook. It will be graded. O
OH conc. H 2 SO 4 O OMe + xs MeOH + H 2 O benzoic acid methyl benzoate- As always, drawing a purification chart may help you underst and the proc edure, and avoid throwing away something you need later. MECHANISM (Fischer esterification) O
R OH O R OH H H O R O H O R O H H H R'OH OH ROH O HR' O ROH O R' H H R OH OR' O R OR' + HCarboxylic
Acid EsterEquilibrium displaced by either
1) water removal
2) ester distillation
3) excess alcohol
The overall process of esterification is one involving an equilibrium among a variety of compounds, and for the reaction to give a high yield; the equilibrium must be shifted toward the products: the desired ester, and water. This can be accomplished either by removing one or more of the products from the reaction mixture as they are formed or by using a large excess of one of the starting reagents. The effect of the latter approach is obvi ous from c onsideration of the mass law relati ng starting materials and products (equation). Increasing the amount of either the alcohol or the carboxylic acid will result in an increase in the amount of products formed since the equilibrium constant. K, for the reaction-must remain constant at a given temperature, no matter what quantity of either reagent is used. ROH
O + R'OH R OR' O + H 2 O K K = [RCOOR'] [H 2 O] [RCOOH] [R'OH]Problem Assignment THIS PROBLEM MUST BE ANSWERED IN YOUR NOTEBOOK AND WILL BE GRADED. Assuming the equilibrium constant for the esterification of benzoic with methanol is K = 3, calculate the theoretical yield of methyl benzoate expected using the molar amounts used in the experiment (Lab 11, above). Concentrated sulfuric acid is added as a catalyst in the esterification procedure, even though another acid (benzoic acid) is one of the organic reagents used. Why is the sulfuric acid necessary?
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