• # question_answer The total number of isomers formed by ${{C}_{5}}{{H}_{10}}$ is [Bihar MEE 1996] A) 2 B) 3 C) 4 D) 5 E) None of these

(1) $\underset{\text{Pent-1-ene}}{\mathop{C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}-CH=C{{H}_{2}}}}\,$ (2) $\underset{\text{Pent-2-ene}}{\mathop{C{{H}_{3}}-C{{H}_{2}}-CH=CH-C{{H}_{3}}}}\,$ (3) $\underset{\text{2}-\text{Methyl}-\text{1}-\text{butene}}{\mathop{C{{H}_{3}}-C{{H}_{2}}-\underset{C{{H}_{3}}}{\mathop{\underset{|\,\,\,\,\,\,\,\,\,}{\mathop{C\,\,=\,\,}}\,}}\,C{{H}_{2}}}}\,$ (4) $\underset{\text{2}-\text{Methyl}-\text{2}-\text{butene}}{\mathop{C{{H}_{3}}-CH=\underset{C{{H}_{3}}}{\mathop{\underset{|\,\,\,\,\,\,\,\,}{\mathop{C\,\,\,\,\,}}\,}}\,-C{{H}_{3}}}}\,$ (5)