By What is a Br radical?
The bromine radical removes a hydrogen atom from the methane. That hydrogen atom only needs to bring one electron with it to form a new bond to the bromine, and so one electron is left behind on the carbon atom. A new free radical is formed – this time a methyl radical, CH3 .
Does bromine form reactive free radicals?
The chain is initiated (started) by UV light breaking a bromine molecule into free radicals. These are the reactions which keep the chain going. These are reactions which remove free radicals from the system without replacing them by new ones.
Why is bromination endothermic?
We’ll do the math in a second, but the key difference is that in chlorination, the key propagation step is exothermic and in bromination, the key propagation step is endothermic. This is because chlorination forms a strong H-Cl bond (103 kcal/mol) and bromination forms a much weaker H-Br bond (87 kcal/mol).
How do you add Br to alkane?
Reaction with bromine gives an alkyl bromide. Unsaturated hydrocarbons such as alkenes and alkynes are much more reactive than the parent alkanes. They react rapidly with bromine, for example, to add a Br2 molecule across the C=C double bond.
How are the initial Br radicals formed?
Question: The Free-Radical Bromination mechanism follows three steps. How are the initial Br’ radicals formed? (Circle one) The sigma_CC bonds in the hydrocarbon donate a single electron to the bromine, Light or heat breaks the Bromine-Bromine bond in Br_2 The.
Why chlorination is faster than bromination?
Chlorination is faster than bromination because chlorine is more reactive.
Is bromination better than chlorination?
Bromination of alkanes occurs by a similar mechanism, but is slower and more selective because a bromine atom is a less reactive hydrogen abstraction agent than a chlorine atom, as reflected by the higher bond energy of H-Cl than H-Br.
Why is Br more selective than CL?
Which Carbocation is the most stable?
tertiary carbocation
The carbocation bonded to three alkanes (tertiary carbocation) is the most stable, and thus the correct answer. Secondary carbocations will require more energy than tertiary, and primary carbocations will require the most energy.