chem lab

Lab-1

VCL 2-1: Alkene Halogenation-1

By: Michele Hopkins

Ocean County Community College

Chemistry 283

Virtual Chemistry Lab-Organic

09/14/14

Table of contents

Title Page……………………………………. Page 1

Table of Contents…………………………Page 2

Abstract………………………………………. Page 3

Introduction………………………………....Page 3

Experimental Details …………………..Page 4

Results ……………………………………….Page 5-6

Discussion………………………………….Page 7-8

Conclusion and Summary ………….Page 9

References…………………………………Page 9

Abstract

This lab is used to show how to determine when a reaction has reached completion. It is also used to describe the polarity of the reaction and how to know when the reaction is polar, non-polar, or has intermediate polarity. This lab focuses on determining this using a TLC test, which is performed several times during the reaction. The TLC is also performed using organic material formed. This lab primary goal is to teach about polarity, TLC test, reaction completion, and to teach organic chemistry students some basic chemistry principles as applied in this lab.

Introduction

The purpose of this lab is to prepare a demonstration of the Alkene and Halogenation This will be an electrophilic alkene addition reaction where the B-bond is broken and two new covalent bonds are formed. I will examine the product carefully to determine the new functionality. Keep in mind the mechanism and form the more stable, most substituted carbocation intermediate.

Experimental Data

1. The starting materials were obtained from the stock room

a. Round Bottom Flask

b. Et20 (Diethyl ether) MCHxene

c. 1-menthyl-1-cyclohexene

d. m-chloropebenzoic Acid

2. The Et20 and the MCHxene were added to the flask

3. The flask was placed on the stir plate

4. Sulfuric acid (H2SO4) was added to the flask along with the other starting materials

5. A heating mantle was added under the flask to heat the mixture

6. A condenser was added to the flask so that the mixture can be refluxed

7. Nitrogen gas was added to maintain inert atmosphere and as well to prevent pressure build up during the reaction

8. The stir Plate was turned on and the reaction started

9. A TLC measurement was done at the begin of the reaction

10. A TLC test was done 15 minutes after the reaction had begun

11. Various TLC test were on at different time intervals as to record when the reaction came to completion.

12. The reaction mixture was added to a separatory funnel

13. HCl aqueous reagent was added to the funnel

14. Two thin layers of organic and aqueous phase were observed in the funnel

15. A TLC measurement was performed on the organic layer in the funnel

16. All lab materials were cleaned up and put away

Results

TLC Measurement – Stirred Mixture

5: 41pm (Start of Reaction) 5:47pm 5:52pm 5:57(complete)

TLC Measument- Funnel Organic TLC –Stired Complete vs. Organic

Organic Stired Organic

IR1

NMR1

Discussion

During the reaction we saw the mixture travel

Questions

1. Why are the spots the same for both the right and left lanes at the start of the reaction?

2. What is the new spot formed after 15 minutes?

a. The new spot is a result of products forming in the reaction.

3. What has happened to the size of the starting material spots? Why? (15 minute point)

4. How much time did it take to complete the reaction?

a. The reaction was started at 5:41pm and was observed to be complete by the TLC measurement at 5:57pm. This means the entire reaction took 40 minutes. There is however room for error because constant TLC test were on done, but instead done every 15 minutes or so.

5. What are the Rf value for the starting material and products?

a. The Rf value are

6. What can you say about the relative polarities of the starting materials and the products?

Conclusions and Summary

References

Organic Chemistry, Seventh Edition, Paula Yurkanis Bruice

Virtual Chemistry Lab: Organic

Virtual ChemLab v2.5 Organic Synthesis and Organic Qualitative Analysis- Laboratory Workbook Student Manual

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