Nucleophilic Substitution Lab Sources Of Error

20 All Pages 20 A Greener Bromination of Stilbene Acetylation of Ferrocene Derick's BRI Experience Electrophilic Aromatic Iodination of Vanillin Gas Chromatography Lab Jacquie's Bend Research Reflection Nucleophilic Substitution Reactions Preparation of

Nucleophilic Substitution Reactions Lab Results

Cyclohexene Add Add "All Pages" Done Nucleophilic Substitution Reactions Edit 0 29 … 0 reactivities of alkyl halides in nucleophilic substitution reactions lab Tags No tags Notify RSS Backlinks Source Print Export (PDF) Introduction Nucleophilic substitution reactions occur as either a one (SN2) or two reactivities of alkyl halides lab results (SN1) step process. An SN2 reaction is one in which a nucleophile makes a new bond to an electrophile while the electrophile's existing bond to a leaving group (LG) is simultaneously broken. Because both the nucleophile and

Nucleophilic Substitution Reactions Of Alkyl Halides Lab Conclusion

electrophile are simultaneously involved in the reaction, the rate of the reaction is determined by the concentrations of both molecules and is expressed as: rate=k[nucleophile]x[electrophile]. An SN1 reaction is one in which an LG leaves behind an electrophile that forms a carbocation intermediate.Once this carbocation is formed, a nucleophile makes a new bond to it and the substitution is complete. Because the carbocation must be formed before the nucleophile can attach, the rate of the reaction is determined only by the concentration of the electrophile and is expressed as: rate=k[electrophile]. However, the rate of reaction can be effected by whether it is performed in a polar protic or polar aprotic solvent. The purpose of this lab is to observe the effects of these two solvents on the reaction between tert-Butyl chloride and NaOH.Whoopsie! WATER is the nucleophile, not hydroxide. In this reaction, the LG (chlorine) leaves creating a tertiary carbocation. The nucleophile (OH-) attaches to the carbocation and forms tert-Butanol. The mechanism is illustrated below with OH- playing the part of the nucleophile (NU-). In this lab, the solvents that will be used to observe the effects of a polar protic solvent and a polar aprotic solvent on an SN1 reaction are acetone and isopropanol. For this experiment, the polar aprotic solvent acetone will be tested and compared to the results of other technicians using the polar protic solvent isopropanol for differences. As a byproduct of the reaction, hydrochloric acid will be produced and the pH of the mixture will become more acidic as the reaction proceeds. The rate of the reaction will be measured by using an acid-base indicator in the reaction mixture. The indicator will change color when the reaction generates enough acid. This will allow rate of reactions to be

Files Members Favorites 20 All Pages 20 home Acylation of Ferrocene Bromination of Stilbene Electrophilic Aromatic Iodination of Vanillin LAB 1 Melting points LAB 2 Crystallization LAb 3 Distillation of Acetone Lab 4 Sublimation Lab 5 Extraction and Separation of a Mixture Nucleophilic Substitution Reactions (7TH INNING) Preparation and Distillation of Cyclohexene TR BRI VISIT Add Add "All Pages" Done Nucleophilic Substitution Reactions (7TH INNING) Edit 0 26 … 0 Tags No tags Notify RSS Backlinks Source Print Export (PDF) Introduction: One of the most important features for the success of a planned SN1 reaction is the selection of a suitable solvent. In organic chemistry, https://pipettedream.wikispaces.com/Nucleophilic+Substitution+Reactions nucleophilic substitution is a reaction in which an electron rich nucleophile selectively bonds with the positive or partially positive charge of an electrophile which was attached to a displaced leaving group. This can be performed in an SN1 two-step reaction or SN2 biomolecular reaction. In order to determine a suitable solvent a few factors must be considered. One factor when choosing a solvent includes solubility which allows reagents to be in the same https://ch337tyronespowerhour.wikispaces.com/Nucleophilic+Substitution+Reactions+(7TH+INNING) phase as the molecules and allows them to collide and react. Another factor is that the solvent needs to be unreactive towards the reagents and last how the solvent will affect the rate of reaction. In the following experiment the effects, if any, of the solvents acetone and isopropanol in an SN1 (two-step nucleophilic substitution) reaction are analyzed. To do this an acid-base indicator will be added to a mixture to monitor the production of acid as the reaction proceeds, although initial knowledge of SN1 reactions assumes that polar protic solvents will increase the rate of reaction. Acid indication allows for measurement of the dependent variable. This allows for further analysis in deciding the relationship of the solvent and reaction progress. Procedure: This lab exercise was devised by Carol Higginbotham, Ph.D. Professor of Chemistry at Central Oregon Community College and Oregon State University - Cascades Campus. Inspiration for this lab activity comes from the POGIL project, especially Frank Creegan, professor emeritus at Washington College, and from Ken Doxsee and Jim Hutchison’s laboratory text “Green Organic Chemistry, Strategies, Tools, and Laboratory Experiments.” please cite me (CH) as the source o this procedure to you. I worked hard on it! :) Materials: - (five) 25mL Erlenmyer flasks - magnetic stirrrer - stir bar - graduated glass pipettes -

Get started today for free * The material on this site is created by StudyBlue users. StudyBlue is not affiliated with, sponsored by or endorsed by the academic institution or instructor. StudyBlue New-jersey Rutgers University - New Brunswick/Piscataway Chemistry https://www.studyblue.com/notes/note/n/nucleophilic-substitution/file/395007 Chemistry 311 Govindarajoo Nucleophilic Substitution Krishna S. Created: 2009-04-07 Last Modified: 2009-04-07 File Size: 4 Views: 2038 Advertisement Nucleophilic Substitution What factors affect SN1 reactions? concentration of alkyl halide conducted in polar protic solvent to form a stable carbocation stable carbocation – rate-determining step tertiary > allyl, benzyl > secondary leaving groups I > Br > Cl leaves a racemic mixture increase in temperature increases rate concentration of nucleophine does not matter What factors affect SN2 nucleophilic substitution reaction? concentration of alkyl halide and nucleophile conducted in polar aprotic solvent because it dissolves the ionic nucleophile without solvating it by hydrogen bonding methyl > primary > secondary leaving groups I > Br > Cl leaves an inverted configuration increase in temperature increases rate in crease in nucleophile increases rate What are the relative rates of reactions? Why? SN1 is determined by the rate of carbocation formation It is slow because it is a two-step reaction nucleophilic substitution reactions SN2 is fast because it is all in one step and concerted Why is it important to have exactly the same amount of alkyl halide and nucleophine in each tube? because different amounts will vary the rates of reaction in each test tube and add another variable to the experiment How would there be a false positive in a reaction? excess alkyl halide can transform alkyl halide into behaving as a solvent nucleophile is not soluble in the solvent Why don’t vinyl and aryl halides undergo SN1 or SN2 reaction? SN1 – because they do not form stable carbocations SN2 – because nucleophile is repelled by electrons in double bond What are the products when alkyl halide is chiral? Why? SN1 – product will still be 50:50 mixture of enantiomers because the planar intermediate can form a bond with the nucleophile on either face SN2 – product will be of opposite chirality because of inversion of configuration Why don’t Br- and Cl- attack the alkyl iodides that form in the SN2 reaction? because NaCl and NaBr precipitate leaving no free Br- or Cl- ions in solution to attack alkyl iodide What factors promote SN2 in the NaI in acetone? acetone is a polar aprotic solvent I- is a good leaving group and a good nucleophile What factors hinder SN2 in the silver nitrate in ethanol reaction?