Question

12 multiple choice 2 points hbr can be added to an alkene in the presence of peroxides (roor). what function does the peroxide serve in this reaction? radical chain initiator electrophile nucleophile acid catalyst

Explanation:

When HBr is added to an alkene in the presence of peroxides (ROOR), the peroxide first undergoes homolytic cleavage to generate alkoxy radicals (\(RO\cdot\)). These alkoxy radicals then abstract a hydrogen atom from HBr to form an alcohol (\(ROH\)) and a bromine radical (\(Br\cdot\)). The bromine radical is the key species that initiates the radical chain reaction with the alkene.

• An electrophile is a species that is electron - deficient and accepts electrons. In this reaction, the peroxide is not acting as an electrophile.
• A nucleophile is an electron - rich species that donates electrons. Peroxides do not have the characteristics of a nucleophile in this reaction context.
• An acid catalyst typically donates a proton (\(H^{+}\)) to start a reaction. Peroxides do not function as acid catalysts in the HBr - alkene addition reaction.

So, the peroxide serves as a radical chain initiator.

Answer:

radical chain initiator