The number of structural and configurational isomers of a bromo compound, `C_5H_9Br`, formed by the addition of `HBr` to 2-pentyne respectively, is:

Options

A. 1 and 2
B. 2 and 4
C. 4 and 2
D. 2 and 1

Answer

B

Explanation

`underset("Pent-2-yne")(CH_(3)-C-=C-CH_(2))-CH_(3)overset(+HBr)rarr CH_(3)-CH=overset(Br)overset(|)(C )-CH_(2)-CH_(3)+CH_(3)-overset(Br)overset(|)(C )=CH-CH_(2)-CH_(3)`
As such two structural isomers are possible. For each structural isomer two geometric isomers are possible. Thus, in all, there are four configurational isomers.