Bromine, Br2 reacts significantly less with butane than with but-2-ene and but-2yne
a. explain this difference in reactivity.
b. explain what must be done in the laboratory to allow bromine to react with alkanes.
c. Describe the reactions that would occur for but-2-ene and but-2-yne with bromine. Assume that excess bromine is present
d. What is type of reaction of butane with bromine?

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Accepted Answer

∻Solution∻ ‖ 1 ⋮ **Explain the difference in reactivity**: Bromine, $Br_2$, reacts significantly less with butane than with but-2-ene and but-2-yne because butane is a saturated hydrocarbon (alkane) with only single bonds, making it less reactive. But-2-ene and but-2-yne are unsaturated hydrocarbons (alkene and alkyne, respectively) with double and triple bonds, which are more reactive due to the presence of $\pi$-bonds that are easier to break. ‖ ‖ 2 ⋮ **Laboratory conditions for alkane reaction**: To allow bromine to react with alkanes in the laboratory, ultraviolet (UV) light or heat is typically required to initiate the reaction. This is because alkanes are relatively unreactive and need an energy source to break the $C-H$ bonds and form free radicals. ‖ ‖ 3 ⋮ **Reactions of but-2-ene and but-2-yne with bromine**: - For but-2-ene ($CH_3-CH=CH-CH_3$), the reaction with excess bromine ($Br_2$) will result in the addition of bromine across the double bond, forming 2,3-dibromobutane ($CH_3-CHBr-CHBr-CH_3$). - For but-2-yne ($CH_3-C≡C-CH_3$), the reaction with excess bromine will result in the addition of bromine across the triple bond, forming 2,3,3,4-tetrabromobutane ($CH_3-CBr_2-CBr_2-CH_3$). ‖ ‖ 4 ⋮ **Type of reaction of butane with bromine**: The reaction of butane with bromine is a substitution reaction, specifically a free radical halogenation, where a hydrogen atom in butane is replaced by a bromine atom. ‖ ∻Answer∻ ⚹ Bromine reacts less with butane due to its saturated nature, requiring UV light or heat to react. But-2-ene and but-2-yne react with bromine via addition reactions, forming dibromo and tetrabromo compounds, respectively. Butane undergoes a substitution reaction with bromine. ⚹ ∻Key Concept∻ ⚹ Reactivity of hydrocarbons with bromine ⚹ ∻Explanation∻ ⚹ Alkanes are less reactive and require energy to react with bromine, while alkenes and alkynes react more readily due to their unsaturated nature. ⚹◊What type of reaction occurs when butane reacts with bromine?⍭ Generate me a similar question◊

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