question_answer 20)

An alkene 'A' contains three C-C, eight C-H \[\sigma \]bonds and one C-C \[\pi \] bond. 'A' on ozonolysis gives two moles of an aldehyde of molar mass 44u. Write IUPAC name of 'A'.

Answer:

An aldehyde 'A' with molar mass 44u is\[C{{H}_{3}}CH=O\] (Ethanal). Since, two moles of ethanol are obtained by ozonolysis of alkene 'A'. \[\underset{Ethanal}{\mathop{C{{H}_{3}}CH=O}}\,+\underset{Ethanal}{\mathop{O=HC-C{{H}_{3}}}}\,\] Now remove the oxygen atoms and join them by a double bond, the structure of alkene 'A' is: \[\underset{But-2-ene}{\mathop{C{{H}_{3}}CH=CHC{{H}_{3}}}}\,or\,H-\underset{\underset{\text{H}}{\mathop{|}}\,}{\overset{\overset{\text{H}}{\mathop{\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}}\,-\underset{\underset{\text{H}}{\mathop{|}}\,}{\mathop{C}}\,=\underset{\underset{\text{H}}{\mathop{|}}\,}{\mathop{C}}\,-\underset{\underset{\text{H}}{\mathop{|}}\,}{\overset{\overset{\text{H}}{\mathop{\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}}\,-\text{H}\] It has three C-C, eight C-H \[\sigma \] bonds and one C-C \[\pi \] bond.