Question

What is/are the product(s) of
CH2=CHCH=CH2 + HBr?

Answer 1

CH2-CHBr-CHBr=CH2

Answer 2

HBr addition to the compound here shall take place through the Markownikoff rule. that is, the Bromine ion gets attached to that Carbon which is attached to most carbons. so, if excess of HBr is taken, Br attaches to both C2 and C3. if not in excess, then to any of the C2 and C3 with equal probability. no major or minor product as such.