Relative Rates: Free-Radical Bromination

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BroIn this experiment of the relative rates of free-radical chain bromination, we were expected to be able to determine the relative reactivates of the many types of hydrogen atoms involved toward bromine atoms. Bromination is defined to be a regioselective reaction meaning bromine has preference of making or breaking a bond over all other directions that it may have had available. In this case, Markovnikov’s rule is revealed to be the case in this situation that states that adding a protic acid represented as HX to an alkene (sp2 hybridized), the hydrogen from that HX would be attracted to a carbon with the least alkyl groups and the halide (X) would become more attracted and will attach to the carbon containing more alkyl groups. Within the intermediate stage of the bromination reaction, the bromine radical will have already formed and the electronegatively charged radical will have a choice of how to protonate in order to create a stable carbocation. In order to determine these sp3 hybridized carbons stability, it can be determined by knowing that while comparing, if there are less alkyl groups attached to a carbocation, then there would not be enough electrons to slightly mask over the positive charge on that certain carbocation. Due to this, the more alkyl groups that are attached, the more stable the carbocation would be due to the fact that the electron flow in the electron cloud slightly donates to the carbocation making it almost completely stable. During the experiment, we were expected to organize two groups of tubes with methylene chloride with their respective hydrocarbon (10 drops) as well as the addition of a small amount of bromine. One group of tubes was set in the light and one was set in the dark and when compared, you were already able to see that the ethylbenzene and toluene were the fastest to react in both situations. Due to this fact we can tell since they were the fastest reacting, they can be associated with the fact that they were more...
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