The total number of acyclic isomers, including the stereoisomers, with formula `C_(4)H_(7)Cl` is

Options

A. 11
B. 12
C. 9
D. 10

Answer

B

Explanation

CH CI is a monochloro derivative of C,H, which itself exists in three acyclic isomeric forms.
`underset("Its four C.s are different")underset(I)(CH_3CH_2CH=CH_2)` `underset("It has 2 types of carbon")underset(II)(CH_3CH=CHCH_3)`
`CH_3-overset(CH_3)overset(|)underset("It has 2 types of carbon")underset(III)C=CH_2`
Four monochloro derivatives of I
`overset(Cl)overset(|)CH_2CH_2CH=CH_2` `underset("optically active d and l isomers")(overset(Cl)overset(|)(CH_3"*"CHCH)=CH_2)`
`overset(Cl)overset(|)CH_3CH_2C=CH_2` `underset("cis and trans isomers")(CH_3CH_2CH=CHCl)`
Hence total isomers forms I=6
Two monochloro derivative if II
`underset("cis and trans isomers")(overset(Cl)overset(|)(CH_2CH)=CHCH_3)` `underset("cis and trans isomers")(overset(Cl)overset(|)(CH_3C)=CHCH_3)`
Hence total isomers form II=4
Two mnochloro derivates from III
`CH_3-overset(CH_2Cl)overset(|)C=CH_2` `CH_3-overset(CH_3)overset(|)C=CHCl`
Grand total of acyclic isomers = 6+4+2 = 12