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Unformatted text preview: CHM 2201 Fall 2009 Department of Chemistry Organic Chemist ry Lab I Villanova University Page 1 of 5 Nucleophilic Substitution of Alkyl Halides Experimental Procedures & Notes for Experiments 17 A, B, and C Chapter 17 in Bell, Clark and Taber, pgs 188 - 191 Carry out this experiment in your hood. Alkyl halides are toxic; avoid breathing vapors and skin contact. You will be using warm water baths in this lab. A Styrofoam cup placed in a beaker (for stability) will be used as your water bath, but you should immediately start to heat some water in a 400 mL beaker on your hotplate so that you have a supply of hot water ready to add to the Styrofoam cup to adjust the temperature as needed. You will also need a timing device of some kind. Experiment A. Structural Effects on S N 1 and S N 2 Reactivity Series 1, NaI/acetone (S N 2 conditions) 1. Label two groups of five clean dry test tubes with numerals 1 to 5. 2. In each group of test tubes add 0.2 mL (use a syringe) of the following alkyl halides to the labeled tubes 3. Keep the tubes stoppered with corks or parafilm and leave them covered at all times, before and after adding reagents. Carry out all experiments in your hood! 4. Obtain 15 mL of each of the following solutions: a. 15% NaI/acetone (for Series 1 of Experiment A) b. 1% ethanolic AgNO 3 (for Series 2 of Experiment A) 5. Read/become familiar with steps 6-9 before continuing. 6. With one series of the tubes arranged in order, add in one portion 2 mL of 15% NaI/acetone solution to tube #1 and note the time of the addition on your table. NOTE: Record data/observations in your notebook in a table like that depicted on page 2 . a. NOTE : after this and subsequent additions carefully watch each of the tubes for the formation (this may occur rapidly or slowly) of a precipitate (look for solids on the bottom and/or sides of the test tube ; turbidity or cloudiness is not precipitation) which indicates that the reaction has occurred. CHM 2201 Fall 2009 Department of Chemistry Organic Chemist ry Lab I Villanova University Page 2 of 5 b. Record the time in your table if and when precipitation (look for solids on the sides and/or bottom of the test tube ) begins to occur in each of the test tubes. Cloudiness or a milky appearance is not precipitation. c. Remember to keep the tubes stoppered or covered (Parafilm) before and after adding the NaI. 7. After 2 to 3 minutes, add 2 mL of the NaI/acetone solution to tube #2 and note the time of the addition on your table; observe to see if or when a precipitate forms and note the time in your table. 8. Continue the process of adding 2 mL portions of the NaI/acetone solution to the remaining tubes in the series (#s 3, 4, and 5)....
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