Propyne is treated with excess HBr (no peroxide). The final product is

A1,3-dibromopropane
B1,2-dibromopropane
C2,2-dibromopropane
D1,1-dibromopropane

Answer: C

The first HBr adds by Markovnikov's rule to give 2-bromopropene,

CH X_{3} - CBr = CH X_{2}

. The second molecule also follows Markovnikov's rule, since Br stabilises the adjacent cation by lone-pair donation, so both Br atoms end up on C-2. The product is the geminal dihalide 2,2-dibromopropane.

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