Answer: 2-bromopropane (Markovnikov).
- A 1-bromopropane (anti-Markovnikov)
- B 2-bromopropane (Markovnikov)
- C 1,2-dibromopropane
- D Propyl bromide mixture
Correct answer: B. 2-bromopropane (Markovnikov)
Explanation: Without peroxides (ionic mechanism), HBr adds according to the Markovnikov rule; the H goes to the carbon with more H atoms, giving 2-bromopropane.
SN2 proceeds in a single step with backside attack and inversion of configuration, while SN1 forms a planar carbocation intermediate first, leading to racemisation.
Concept context
Study carbon-halogen compounds: how they are made, how they react via SN1/SN2 and elimination, their stereochemistry, and their environmental impact.