question_answer

The total number of acylic isomers including the stereoisomers (geometrical and optical), with the molecular formula \[{{C}_{4}}{{H}_{7}}Cl\] is

A)  12                                         

B)  11

C)  10                                         

D)  9

Correct Answer: A

Solution :

                 Twelve in all  Six geometrical isomers (i)   (ii) (iii) (iv) (v) (vi)  Two optical isomers (vii) \[C{{H}_{3}}-*\overset{\begin{smallmatrix}  Cl \\  | \end{smallmatrix}}{\mathop{\underset{\begin{smallmatrix}  | \\  H \end{smallmatrix}}{\mathop{C}}\,}}\,-CH=C{{H}_{2}}\] (viii) \[C{{H}_{3}}-*\overset{\begin{smallmatrix}  H \\  | \end{smallmatrix}}{\mathop{\underset{\begin{smallmatrix}  | \\  Cl \end{smallmatrix}}{\mathop{C}}\,}}\,-CH=C{{H}_{2}}\]  Four structural isomers (ix) \[C{{H}_{3}}C{{H}_{2}}-\overset{\begin{smallmatrix}  Cl \\  | \end{smallmatrix}}{\mathop{C}}\,=C{{H}_{2}}\] (x) \[C{{H}_{3}}-\overset{\begin{smallmatrix}  C{{H}_{3}} \\  | \end{smallmatrix}}{\mathop{C}}\,=CHCl\] (xi) \[C{{H}_{3}}-\overset{\begin{smallmatrix}  C{{H}_{2}}Cl \\  | \end{smallmatrix}}{\mathop{C}}\,=C{{H}_{2}}\] (xii) \[ClC{{H}_{2}}-C{{H}_{2}}-CH=C{{H}_{2}}\]