The total number of alkenes possible having the molecular formula `C_(5)H_(10)` is

Options

A. `4`
B. `5`
C. `6`
D. `2`

Answer

C

Explanation

Possible skeletons are
(I) `C-C-C-C-C` , (II) `C-overset(C )overset(|)(C )-C-C` , (III) `C-underset(C )underset(|)overset(C )overset(|)(C )-C`
`C-underset("Pent-1-ene")(C -C-C=C)` ,
From (II), we get three structural isomers, none of which has geometrical isomers:
`overset(1)(C ) = underset("2-Methylbut-1-ene")(underset(C )underset(|)overset(2)(C )-overset(3)(C )-overset(4)(C ))` , `underset("2-Methylbut-2-ene")(underset(1)( C)-underset(2)overset(C )overset(|)(C )=underset(3)(C )-underset(4)(C ))` , `underset("3-Methylbut-1-ene")(underset(4)(C )-underset(3)overset(C )overset(|)(C )-underset(2)(C ) = underset(1)(C ))`
The central `C` of (III) is quaternary and, thus, cannot form a double bnd to give an alkene.