Introduction:
The purpose of this lab was to perform a comparison of relative reactivities of various alkyl halides with two different reagents, sodium iodine in acetone and silver nitrate in ethanol. (Below are the reaction equations). We used different substrates, which were primary, secondary, and tertiary. These substrates included 2-bromobutane, 2-bromo-2-methylpropane, 1-bromobutane ∞-Bromotoluene, bromobenzene, and I-bromoadamantane. This lab helped discover what kind of mechanisms (either SN1 or SN2) are involved in the performed reactions. 1. Sodium Iodine in Acetone:
RX + NaI -----Acetone----> RI + NaX (X=Br) 2. Silver Nitrate in Ethanol:
RX + AgNO3 + EtOH ROEt + AgX + HNO3 (X=Br)
Procedure:
First we attained 5 different test tubes and labeled them with numbers (1 through 5) and added 1.0 mL of NaI acetone to each one. Then we added 2 drops of the correct alkyl bromide to each tube. We used 2-bromobutane, 2-bromo-2-methylpropane, 1-bromobutane, bromocyclohexane, and I-bromoadamantane. We mixed each test tube and observed the reactions for five minutes to see if there is a precipitate. For the ones we did not see a precipitate for, we heated the test tube for 6 minutes at 50 degrees C. For the second part of the lab we attained 6 different test tubes and labeled them with numbers (1 through 6) and added 2.0 ml of 0.1 M silver nitrate to each one. Then we added 1 drop of the correct alkyl bromide to each tube. We used 2-bromobutane, 2-bromo-2-methylpropane, 1-bromobutane ∞-Bromotoluene, bromobenzene, and I-bromoadamantane. We mixed each test tube and observed the reactions for five minutes to see if there is a precipitate. For the ones we did not see a precipitate for, we heated the test tube for 3 minutes at 50 degrees C.
Results:
NaI in acetone reactions: Alkyl Halides | Classification of RX | Observations | Conclusion | 2-bromobutane |